


..^^ 



w 



S 




SCIENCE IN FARMING. 



A TEXT BOOK 



—ON THE— 



principle^ of feridulture, 



INCLUDING A TREATISE ON 



AGRIOULTURAL CHEMISTRY. 



DESIGNED FOR USE IN 



Schools, Granges, Farmers' Clubs, and by Farmers 
and their families. 




(A 



y 

By R. S. THOMPSON. 

'1 ^-:^j^ 






iZi 



\\C'/r 






Published by The Farmers' Advance, 

SPRINGFIELD. OHIO. 

1882. 



COPYRIGHT, 1882, BY R. S. THOMPSON. 



Success in Farming, 

A Series of Practical Talks with Farmers, 

— BY — 

WALDO F. BROWN, 

One of the Most Popular Agricultural Writers in the United 

States. 



Handsomely Printed on Heavy Tinted 

Paper and Elegantly Bound 

in Cloth. 



The Book is Well Arranged and Systematized, and Full 
of Practical Common Sense. 



PRICE, by Mail, Postpaid, - - - - ONE DOLLAR. 



Published by "The Farmers' Advance," Springfield, 0. 



Its twenty-one chapters consider : What constitutes success 
in farming ? selection of farm, management, buildings, 
fences, draining, fertilizing, hired help, implements, wheat, 
corn, grasses, clover, potatos, rye, special crops, fruit, garden, 
stock, poultry, timber, and country homes. 

WHAT IS SAID OF SUCCESS IN FARMING. 

Two Chapters Worth More than the Price of the l-5ook, 

I have received Success in Farming, and I have received 
from two chapters — " Farm Building " and *' Hired Help " — 
benefit worth far more than the price of the book. 

Frankfort, Ohio. A. B. Cline. 



Every Farmer Ought to Have It. 

I have read Success in Farming, and every farmer ought to 
have it. It surjjasses my most sanguine expectations. There 
is no theory about it. It is all facts. A child can under- 
stand it. It only needs to be read to be appreciated. 

Bacon P. 0., Ohio. JosErn Love. 



TO SLL WHO LIBOR TO RDYSNCE THE ¥ELF11RE, SND INCREASE 

THE INTELLIGENCE SND HSPPINESS OF MANKIND. 

THIS BOOK IS DEDICATED. 



INTKODUCTION. 

The preparation of this book was suggested by the 
number of inquiries I have received, both personally 
and by letter, for a book treating on the elements of 
agriculture. 

Careful examination of all the books on the subject 
I could find, satisfied me that although many of them 
were excellent, none exactly met the needs of my 
questioners. 

Some of the books on the subject have been pub- 
lished many years, and, as many of the most impor- 
tant investigations in this direction have been made 
in the past few years, these books are out of date. 

Some books of this class were well adapted for the 
student who was acquainted with the elements 
of chemistry and physiology, but could not be under- 
stood by those who had no knowledge of these sciences. 
Other books were so large and expensive that they 
exceeded the limits of the average farmer's time and 
purse. 

In others the attempt has been made to condense 
the subject into such small space, that it had been 
impossible to treat it in a clear or satisfactory manner. 

The great difiiculty in the production of such books 
has been the fact that the men who have fitted them- 
selves for their preparation, by lives spent in scientific 



Vi SCIENCE m FARMING. 

research, have, by the necessities of the case, been so 
separated from the great body of the farmers of the 
country, that it was impossible for them to understand 
their needs. 

The only special fitness that I claim for the prepa- 
ration of a work of this character, is an intimate 
acquaintance with the farmers ofour country, a strong 
attachment to the occupation of agriculture, and an 
earnest desire to see it lifted to its proper place as one 
of the most honorable, pleasant, and intellectual 
occupations that can be followed by man. 

It is not the design of this book to lay down rules 
concerning the amount of manure to apply to an acre 
— nor the exact depth to which grain should be planted, 
nor the number of pounds of hay that should be fed to 
a cow. These are things which constantly vary with 
locality, season and circumstance, and which each 
farmer must, to a certain extent, determine for him- 
self. 

This book teaches the laws and principles that 
underly the practical work of the farm, a knowledge 
of which will enable a farmer to intelligently construct 
his own rules. 

I have not attempted to write a book that can be 
read merely for entertainment, without mental effort 
— as a novel, or a fairy tale. It would not be possible 
to write such a book and convey the information de- 
sired. There is no "primrose path to learning." 

The important scientific knowledge that is now 
proving of such great value to the farmer was all ob- 
tained by patient toil. They who would get the benefit 
of this knowledge must be willing to give for its ac- 
quirement at least a moderate amount of mental 
labor. 



INTRODUCTION. Vll 

I have earnestly endeavored to make every portion 
of the work so clear that it can be understood by any 
who are willing to expend as ^reat amount of mental 
effort as is needed in the acquirements of other studies. 
Greater simplicity than this can only be obtained by 
the sacrifice of value. 

Each chapter in this book prepares the way for that 
which follows, and it would be as unwise to expect to 
understand the latter chapters before mastering 
those which precede it, — as it would be to expect a 
schoolboy to work a sum by the rule of three, before 
he understood the multiplication table. 

I have not attempted to avoid the use of scientific 
names and terms, my object has been to enable the 
student to understand not only this book, but the 
writings of others. I have therefore first explained the 
meaning of scientific terms and then made use of 
them. 

The book is not one of mere theory. It gives the 
results of long continued and careful experiments 
made by the most competent men in the world. 

No attempt has been made to explain the methods 
by which the facts given have been ascertained, nor 
space used in aruguments to prove that they are facts. 
The aim has been to give the facts themselves, leav- 
ing the explanation of the methods by which they 
have been ascertained for books intended for scientific 
men. 

It may be that some readers who have had the ad- 
vantages of a liberal education, may consider the book 
too simple, and that too much pains have been taken 
to explain that which can be understood without ex- 
planation. 

I would ask such to remember that this book is 



Vni SCIENCE IN FARMING. 

designed for men, many of whom have not had the 
opportunities for the higher education that is given to 
the young people of to-day. 

It is a book intended to be studied — by the farmer 
and his family around the fireside, in the district school, 
in the grange hall, and farmers' club. 

If, by its study, some are enabled to see more of the 
beauties, and understand more of the mysteries con- 
nected with science in farming, and inspired to greater 
zeal in their efforts to lift the occupation of agriculture 
to the honored place which is of right its own, I shall 
fee] repaid for the days and nights of labor that have 
been expended in its preparation. R. s. t. 



CONTENTS. 



PAGE 

CHAPTER I. 

SCIENCE IN FARMING 13 

CHAPTER II. 

SCIENCE IN ITS ELEMENTS. 

§ 1- Terms Used 17 

§ 2. The Foundation of Science. ..... 19 

§ 3. Arithmetic . . 20 

CHAPTER III. 

SCIENCE IN HEAT AND ENERGY. 

§ 1. Their Nature 23 

§ 2. Transference of Heat 25 

§ 3. Practical Application ...... 27 

CHAPTER IV. 

CHEMISTRY. 

§ 1. Its Nature and Language 30 

§ 2. Chemical Laws 33 

§ 3. Chemical Symbols and Formula . ... 36 

§ 4. The Elements , . 37 

§ 5. The Compounds . . 41 

§ 6. Compounds of Acids and Bases . . . . 47 

§ 7. Organic Chemistry . . . . . . . 51 

4 8. Combustion and Decay . . . . . . 58 



X gClENCE IN FARMma. 

PAGE. 
CHAPTER V. 

SCIENCE IN AIR. 

§ 1. Its Composition and Characteristics .... 61 

§ 2. Importance of Each Constituent .... 64 

§ 3. Summary 68 

CHAPTER VI. 

SCIENCE IN SOILS. 

§ 1 Origin of Soils 69 

§ 2. Composition and Classification of Soils . . .70 

§■ 3. Properties of Soils 71 

>) 4. Chemical Characteristics of Soils . . . .77 

§ 5. Mechanical Conditions of Soils .... 83 

6 6. Value of Sand, Clay and Humus .... 86 

^ 7. Practical Application 88 

CHAPTER VII. 

SCIENCE IN PLANT GROWTH. 

^ 1. Composition of Plants 91 

§ 2. Germination 94 

^ 3. How the Plant Grows 95 

§ 4. Formation of Seed . 99 

§ 5. Summary and Practical Application .... 101 

CHAPER VIII. 

SCIENCE IN ANIMAL LIFE. 

§ 1. Composition of the Animal 104 

§ 2. Animal Nutrition 105 

^ 3. Uses of Food in the Body 107 

§ 4. Disposition Made of Food . . . . . . 108 

§ 5. Effect of Insufiicient Food 110 

§ 6. Effects of Exercise and Exposure to Cold . . .111 



INDEX. XI 

PAGE. 
CHAPTER IX. 

SCIENCE IN FOODS. 

§ 1. Food Constituents 113 

§ 2. Composition of Foods 114 

§ 3. Digestibility of Foods 118 

§ 4, Valuation of Foods 121 

§ 5. Albuminoid Ratio 124 

■ CHAPTER X. 

SCIENCE IN FEEDING. 

§ 1. General Principles 129 

§ 2. Proper Food for Young Animals .... 133 

§ 3. Proper Food for Producing Milk .... 135 

k 4. The Fattening Animal 139 

§ 5. The Working Animal 144 

§ 6. Summary 145 

CHAPTER XI. 

SCIENCE IN FERTILIZERS . 

§ 1. General Principles ....... 147 

§ 2. Rendering Plant Food Available .... 149 

§ 3. Manures .152 

§ 4. Farm-Yard Manure 154 

§ 5. Manure from Diflferent Animals .... 159 

§ 6. Relation of Food to Manure .... 160 

§ 7. Valuation of Manure ..... 166 

§ 8. Commercial Fertilizers ..... 173 

^ 9. Adaptation of Manures to Crops .... 176 

§ 10. Summary ........ 178 



AUTHOE'S ACKNOWLEDGMENTS. 

Had the writer paused at every step of his progress 
to explain the sources whence his information had 
been obtained, as much space would have been occu- 
pied in acknowledgments as in statement of facts, 
and the design of the work — as a condensed text-book 
of information — would have been defeated. 

In addition to the standard text-books of science, 
special acknowledgments are due to those two valua- 
ble works of Johnson's, How Crops Grow and How 
Crops Feed ; also to Harris' Talks on Manures, and 
to Warrington's Chemistry of the Farm — a book that 
contains a great amount of valuable information in 
small space. 

Acknowledgments are also due to friends who have 
kindly aided the work with good words and valuable 
suggestions all the way, among whom should be 
named W. I. Chamberlain, Secretary of the Ohio 
State Board of Agriculture, Professor N. W. Lord, 
analytical chemist of the Ohio State University, L. 
N. Bonham, agricultural editor of the Cincinnati Com- 
mercial, Waldo F. Brown, author ot Success in Farm- 
ing, J. W. Ogden, and others. 



CHAPTER I. 



SCIENCE IN FARMING. 

1. Definition of Science. — Webster defines science 
as " Truth ascertained" — " that which is known" — 
" knowledge duly arranged." 

According to this definition, facts ascertained and 
duly arranged constitute science, and study of science 
consists in studying established facts, their arrange- 
ment and mutual relationship. A mere compilation 
of facts, without arrangement and without regard to 
the relations existing between those facts, is not 
science. 

2. Science and Practice. — A distinction is often 
made between scientific and practical knowledge. 
Strictly speaking, all scientific knowledge is practical, 
as it is a knowledge of facts, and practical knowledge 
becomes scientific when duly arranged. 

3. Scientific knowledge is the result of careful ex- 
periments conducted with an intelligent purpose. 

4. In common language, practical knowledge is the 
knowledge of a fact, and scientific knowledge the 
knowledge of the principles and causes on which that 
fact depends. 

5. Illustration. — A farmer learns by experience 
that the manure produced by cattle fed on clover hay 



14 SCIENCE m FARMING. 

is more valuable than that produced by cattle fed on 
straw. This is practical knowledge. Afterwards he 
learns that this difference is due to the fact that clover 
contains a larger amount of a substance called nitro- 
gen, than straw, and that this nitrogen is valuable as 
a manure. This is scientific knowledge, and this en- 
ables him to know that manure produced by cattle 
fed on any other substance containing much nitro- 
gen will also be of special value, and he can consider 
this fact in making his selection of foods. 

6. The Farmer a Manufacturer. — The business of 
the farmer is to produce certain articles such as 
wool, cotton, beef, ]3ork, butter, cheese, etc. These 
can only be produced by bringing together other sub- 
stances already in existence, and by combination and 
re-arrangement changing them into the substances de- 
sired. The farmer is therefore as truly a manufac- 
turer as the man who makes plows or sewing ma- 
chines. 

7. The soil and air are the sources from which the 
farmer draws his supplies of raw material, and the 
plant and animal are the machines by which he works 
up this raw material into useful manufactured pro- 
ducts. 

8. If the farmer would be successful, he must 
therefore have a knowledge concerning the substances 
from which his manufactured goods are to be pro- 
duced, and of the sources from which he is to obtain 
them. He also needs to be well acquainted with the 
machinery he is using, and with the laws that govern 
its working. This knowledge is the" science of farm- 
ing." 

9. In the earlier days, when the virgin soil was 
ready to produce a crop if the opportunity were pro- 



SCIENCE IN FARMING. 16 

vided — when the customs of life were simple, and the 
farmer's needs were few, it was possible for men to 
obtain a living from the soil though they knew but 
little of the " science of farming." But with the 
change in the condition of our soil, the customs of so- 
ciety, and in the manner of life upon the farm — it 
has become necessary that a better knowledge of this 
science should be diffused among the people, and the 
day is rapidly drawing near when none can hope for 
success in farming without a knowledge of science in 
farming. 

10. Chemistry. — An acquaintance with the ele- 
ments of chemistry is the key which opens the door 
to the mysteries of agriculture — for the growth of the 
plant and the life of the animal are the result of op- 
erations controlled by chemical laws. 

As well might the child expect to read without 
learning his letters, or the musician to understand 
music without learning the notes, as the farmer 
to'understand his occupation without having first 
learned the elements of chemistry. Letters are not 
reading ; notes are not music, and chemistry is not 
farming ; but as the child cannot read without a 
knowledge of his letters, neither can the farmer un- 
derstand the science of his occupation without a 
knowledge of the elements of chemistry. 

11. Agricultural Chemistry. — Strictly speaking, 
there is no such science. Chemistry and its laws are 
the same, whether applied to the arts, to manufac- 
tures or the farm, and the thorough student must learn 
these laws and principles without expecting to see an 
immediate application. 

12. But although a certain knowledge of the laws 
and principles of chemistry is an essential preparation 



16 SCIENCE IN FARMING. 

for the study of agriculture, there is much of the de- 
tails of this science which may, without detriment, be 
omitted. 

In the treatise on chemistry contained in this work, 
only that is given which is of importance to the 
farmer. 

All that is given should be studied and understood, 
for it is the key, not to this book alone, but to the 
books and writings of scientific men. 

13. The complaint is often made that the writings 
of scientific men are beyond the comprehension of 
the people. The reason is that people have not stud- 
ied the elementary principles of science. 

14. Therefore these elements of science are of the 
utmost importance. They are not only important in 
themselves, and full of beauty and interest, but they 
also prepare the way for wider, deeper, and more in- 
teresting researches. 



CHAPTER 11. 



SCIENCE IN ITS ELEIMENTS. 

§ 1. Te7'ms Used. 

In order to understand scientific facts we must first 
know something of the terms used by scientific men. 

15. Matter. — Everything that has weight or bulk. 
Thus, iron is matter, and so is wood, or gold or air. 
Difi'erent parts of matter are called bodies or sub- 
stances. Matter can change its form — a solid may 
become a liquid or a gas, and a gas may become a 
liquid or a solid — or one substance may enter into 
combination with another, and both lose their former 
characteristics and gain new ones. But in all these 
changes matter is neither created nor destroyed. A 
house is built by bringing and fastening together 
wood and iron and stone and brick and mortar, but 
the house was built, not created — there was no more 
stone and brick and wood and iron in existence after 
the house was built than before. So when a plant or 
animal grows, different substances are gathered to- 
gether and combined to form the plant or animal ; but 
nothing is created. There are no more of these sub- 
stances in existence than before. Matter has only 
changed its form. 

16. If a house is torn down, and the material of 
which it was built scattered, the bricks and wood 



18 SCIENCE IN FARMING. 

and stone and iron are still in existence. So if, 
after the plant is grown we put it on the fire and burn 
it, the matter in the plant changes its form, but is 
not destroyed. If we should carefully collect the 
ashes and smoke and vapor and gas produced by 
burning the plant, we would find they weighed the 
same as the plant before it was burned. It is impos- 
sible to create the smallest particle of matter, and 
equally impossible to destroy it. 

17. Solids, Liquids, Gases. — Matter exists in three 
forms. A solid is a substance the particles of which 
are firmly held together so that they will not move 
upon each other. Iron is a solid. Liquids are sub- 
stances in which the particles readily move upon each 
other and which yet have some attraction for each 
other. AVater is a liquid. A gas is a substance in 
which the particles seem to have no attraction for each 
other. The air we breathe is a gas, or rather a mix- 
ture of gases. 

18. Atoms. — It is supposed that all substances are 
composed of exceedingly small particles, so small 
that no microscope has ever been able to reveal them 
to the eye, and which are called atoms. Between 
these atoms there exists a force that draws them to- 
gether, and another that tends to separate them. 
One is called the attractive, the other the repulsive 
force. When the attractive force is the strongest, 
matter exists in the form of a solid. When the two 
are about equal, in the form of a liquid; and when the 
repulsive force entirely overcomes the attractive, the 
substance is called a gas. 

19. Force is whatever acts on matter to change 
it. Thus the force of heat can change a piece of ice 
into water. Chemical force may cause two substances 



SCIENCE IN ITS ELEMENTS. 19 

to combine, producing a different one. The force of 
gravity will cause a substance when not supported to 
fall to the ground. Like matter, force can neither be 
created nor destroyed. This will be further explained 
in the chapter on Heat and Energy. 

20. Properties of Matter. — Those characteristics 
which serve to distinguish one kind of matter from 
another. Thus it is a property of flint to be hard, of 
wax to be soft, of snow to be white, of charcoal to be 
black. 

21. Element. — In chemistry is a substance that 
cannot be separated into other substances. Thus 
gold is an element ; you may divide it into very min- 
ute portions, but each i3iece, no matter how minute, 
is still gold. Common table salt is not an element, 
but can be separated into two very unlike substances 
which are elements. There are only a little over sixty 
elements known to chemists to-day. 

The term element is often used to represent one of 
the ingredients in a complex compound — as in the 
expression, "The elements lacking in the fertilizer 
were ammonia and potash" — though neither ammo- 
nia nor potash is an element in the chemical sense of 
the term. 

§ 2. The Foundation of Science. 

22. All science is founded on the principle that 
matter is subject to certain definite and unchangeable 
laws, which maybe ascertained, and when ascertained 
will enable us to know positively the results of cer- 
tain causes. Science may be said to rest on the prin- 
ciple that every effect must have a cause, and that 
the same cause, under the same circumstances, will 
always produce the same effect. If it were not for 



20 SCIENCE IN FARMING. 

this principle, scientific progress in any work would 
be impossible. 

23. If a substance is left unsupported, we know it 
will fall directly toward the earth. No other action 
is possible. The fact that wood will float in water, 
and smoke ascend in the air, is not an excexDtion, as 
the wood is suj)ported by the water, and the smoke 
by the air. 

24. If a farmer gets 30 bushels of wheat per acre on 
one field, and only 10 bushels per acre on another, 
the diff'erence is not due to an accident, or a whim of 
the crop ; but to a diff'erent condition of circumstances 
in the two fields. If he can learn what was the cause 
of the good crop in the one field, and secure that cause 
in the other, he will be certain of as good a crop. Of 
course, in practice it is not possible for the farmer to 
control all the circumstances that aff'ect a crop, but 
just so far as he can control those causes he can con- 
trol the result. 

25. A knowledge of science is therefore a knowl- 
edge of the properties of bodies, of the laws that gov- 
ern their action upon each other, and the relations 
that exist between cause and effect. 

§ 3. Arithmetic. 

26. Science being exact, much of its results are to 
be determined only by careful calculations, and it 
will be difficult, if not impossible, for the student to 
master any science without knowing something of the 
rules of arithmetic. We shall assume, therefore, that 
the readers of this book are at least moderately fa- 
miliar with arithmetic, and call their attention to two 
divisions of it only. 

27. Per Cent. — By per cent is meant the number of 
parts in a hundred. Thus, in 100 lbs. of good milk 



SCIENCE m"lTS ELEMENTS. 21 

there are about 87 lbs. of water ; so we say that milk is 
87 per cent water. 

28. The percentage composition of a substance is the 
number of i)arts of each constituent in 100 parts of the 
substance. A great many scientific tables are pre- 
pared, giving the percentage composition of sub- 
stances. 

29. When we know the per cent of any constituent 
and wish to learn the exact amount of that constit- 
uent there would be in a given amount of the sub- 
stance, we multiply the amount of the substance by 
the per cent of the constituent, and divide by 100. 

Thus we find that fat forms about 32 per cent of the 
whole carcass of a fat ox. Now, if we wanted to 
know how many i)ounds of fat there were in a fat ox 
weighing 1,475 lbs., we would proceed thus : ^ a^ n 
To divide by 100, we only need to strike off 3 2 

the two last figures to the right, and call them 

hundredths, and so we get the answer, that an 2 9 4 
ox weighing 1,475 lbs., whose carcass was 32 4 4 2 5 
per cent fat would contain 471 1^-^\ lbs. fat T/^-j qq 

30. Decimals. — It is found very convenient 

in scientific calculations to use principally decimal 
fractions — that is fractions represented in tenths, hun- 
dredths, thousandths, and so on. Decimals are writ- 
ten by putting a period after the figures denoting the 
whole numbers, and to the right of this the figures 
representing the number of tenths, hundredths, thou- 
sandths, as the case may be. One figure to the right 
of the period stands for tenths ; two figures for hun- 
dredths, and three for thousandths. 

Thus 1.9 would be read " one and nine-tenths;" 1.93 
'' one and ninety-three one-hundredths;" and 1.016, 
'' one and sixteen one-thousandths." A cipher an- 



22 SCIENCE IN FARMING. 

nexed to the right of a decimal does not change its 
value ; thus, 1.90 would read " one and ninety one- 
hundredths," which of course is the same as one and 
nine-tenths. A cii3her placed to the left of a decimal 
reduces its value to one-tenth what it was in the for- 
mer place ; thus, 1.09 would be read '' one and nine 
one-hundredths." 

31. It frequently happens that a decimal is used 
without a whole number ; thus, it is said that a good 
soil contains .25 i^er cent of nitrogen, which means 
that it contains twenty-five one-hundredths of one per 
cent, or a quarter of a pound of nitrogen in a hundred 
pounds of soil. 



CHAPTER III. 

SCIENCE IN HEAT AND ENERGY.* 

§ 1. Their Nature. • 

32. The Same Principle. — Heat and energy are dif- 
ferent manifestations of the same principle. Heat is 
said to be a mode of motion. Heat can be changed 
into energy, and energy may be changed into heat. 

33. Illustrations. — If a bar of iron is hammered on 
an anvil, the energy that was used will be expended, 
and the bar of iron will become hot, and the amonnt 
of heat in the iron will be in exact proportion to the 
amonnt of energy expended in the blows. If heat is 
applied to a steam boiler, and the steam ijrodnced used 
in running an engine, tlie lieat of the fire will be ex- 
pended, but instead we have the motion of the ma- 
chinery. If a brake is applied to some i^art of the 
machinery and the motion is stopped, the brake will 
become hot, and the heat will be in exact proportion 
to the amount of energy that had to be overcome. . 

If a pound of ice at 82 degrees is broken and mixed 
with a pound of water at 174 degrees, the ice will be 
entirely melted, and the temperature of the two 
pounds of water will be but 32. One hundred and 
forty-two degrees of heat will have been lost by the 

*The word energy is here used to represent what might be 
called active force, force producing work. 



24 SCIENCE IN FARMING. 

pound of water, and the temperature of the pound of 
water produced from the pound of ice will be no higher 
than that of the ice. The heat had been changed into 
the energy needed to overcome the attraction of the 
particles of the solid ice and change it into a liquid. 

34. If heat is applied to a quantity of water the 
temi)erature of which is 32 degrees, it will gradually 
grow hotter until it reaches 212 degrees ; then the 
water will begin to boil or be changed into steam, but 
the temperature of the steain will be no higher than 
that of the water had been. If the heat is uniform, it 
will take five and a half times as long to change the 
water into steam as it did to raise the water from the 
freezing to the boiling point. This heat has been 
changed into the energy needed to overcome the attrac- 
tion 6f the particles of water for each other and 
change the liquid into a vapor. 

35. When water is poured on quicklime, they 
unite chemically, and the water becomes part of the 
solid slaked lime. The energy that had before kept the 
atoms of water separated is now changed into heat, 
and the mixture is hot, though both the lime and the 
water were cold before mixing. 

36. Place a pan of hot water out of doors on a cold 
winter daj^ The temperature of tlie water will fall 
until it reaches the freezing point and the water be- 
gins to freeze. Then it will remain unchanged until 
all the water is frozen. The energy that has before 
been keeping the atoms of water separated is con- 
verted into heat, as the water becomes solid, and pre- 
vents the further fall of temperature until all the 
water is changed into a solid. 

37. Cannot be Destroyed. — Heat and energy can nei- 
ther be destroyed nor created. In an elementary 



HEAT AND ENERGY. 25 

work, such as this, it would be imiDossible to fully ex- 
plain and illustrate this fact ; but it is an important 
one. Heat and energy must always be derived from 
some source where they have previously been stored. 
The energy that moves our locomotives and keeps our 
factories running, was received from the sun long ages 
ago, in the form of heat and light, stored up by grow- 
ing plants, and is now changed into energy in the fur- 
naces and fire-boxes. 

38. The heat that keeps an animal alive, the force 
which he expends in work and motion, are not created 
by the animal, but are obtained from the food, and 
were originally gathered from the sun. This last 
fact will be more fully explained in the chapter on 
Animal Life. 

39. Specific Heat. — If a pound of water and a 
pound of mercury are both exposed to a uniform 
source of heat, it will require thirty times as long to 
raise the temperature of the pound of water a given 
number of degrees as to raise the temperature of the 
pound of mercury the same number of degrees. That 
is, the water requires thirty times as much heat to 
raise its temperature a given number of degrees as 
would be required by an equal weight of mercury. 
Each substance requires a particular amount of heat, 
IDeculiar to itself, and this amount is called the spe- 
cific heat of the substance. 

The reason for this cannot be exi3lained in this 
work. 

§ 2. Transference of Heat. 

40. Heat moves, or is transferred from one place 
to another by three methods, called conduction, con- 
vection and radiation. 



26 SCIENCE IN FARMING. 

41. Conduction. — If one end of a bar of iron is 
placed in the fire, the heat will pass throngh the iron, 
and the other end will become hot. This is called 
conduction. 

42. Difference in Conduction. — If two similar rods, 
one of copper and one of iron, are heated at one end, 
it will be fonnd that the heat will pass through the 
copper more rai^idly than through the iron, and the 
copper is said to be the better conductor. Substances 
through which heat passes readily are called good 
conductors ; those through which iti3asses slowly are 
called bad conductors. All metals are good conduc- 
tors. Liquids and gases are very poor conductors, 
so poor that they are often called won-conductors. 
Snow is a very poor conductor; hence when the 
ground is covered with snow, the heat it contains does 
not escape, and thus snow protects the crops. 

43. Convection. — When heat is applied to the bot- 
tom of a vessel containing water or some other liquid, 
the particles in immediate contact with the vessel 
become heated ; this causes them to expand and be- 
come lighter, and they rise to the upper ]3art of the 
vessel while the colder portions sink, and in this man- 
ner all the liquid in the vessel becomes heated. This 
is called convection. Gases are heated in the same 
manner. The portion in immediate contact with the 
heated substance becomes warm and rises, and a cir- 
culation is thus established. 

44. Radiation. — If we stand near a stove or other 
heated body, we feel the heat from it, though it is not 
conveyed to us either by conduction or convection. 
All bodies are constantly throwing off heat in straight 
lines, like light. This is called radiation, and heat 
thus transferred is called radiant heat. Radiant heat 



HEAT AND ENERGY. 27 

passes through the air or any gas without imparting 
warmth to it. 

45. Radiation is inliuenced by the color and sur- 
face of the body — a dark, rough surface radiates heat 
more rapidly than a white or polished one. Hence a 
brightly polished coffee-pot will keep coffee hot longer 
than one that is dark and rough. 

46. Absorption of Heat. — When radiant heat strikes 
a body it is, to a greater or less degree, absorbed by 
that body, and warms it. The same surfaces that ra- 
diate heat readily also absorb it readily. If a black 
cloth and a white one are spread on the snow in the 
sun, the black one will rapidly absorb the sun's heat 
and melt the snow beneath it, while the white one 
will not. So a black hat is warmer in the sun than a 
white one, and a black soil gets warm more quickly 
in the spring than one of a lighter color. 

§ 3. Practical Aj^plication. 

47. If a jug of water in the harvest field is covered 
with a thick cloth soaked with water, the heat of the 
sun and air will be converted into energy to change the 
water in the cloth into vaj)or, and the water in the 
jug will remain cool until the water in the cloth has 
been evaj^orated. 

48. A wet cloth worn inside the hat protects from 
the sun's heat. The British troops in India were ena- 
bled to endure the heat only by constantly wearing 
a wet cloth over the head. A shawl or woolen cloth 
hung in the window of a room and kept wet, will 
lower the temi)erature several degrees. Sprinkling 
the walks, grass and trees around a house imparts a 
delightful coolness to the air on a summer day. Tliese 
effects are caused by the conversion of heat into ener- 
gy, required to change water into vapor. 



28 SCIENCE IN FARMING. 

49. Perspiration protects from heat in the same 
manner. If an animal in winter is cansed to perspire 
nncluly by the use of food containing an excess of 
water, heat is wasted. 

50. When the ground is filled with water, the heat 
of tlie sun, instead of warming the soil, is converted 
into the energy required to convert that water into va- 
por, or in other words, the heat is used for pumping 
instead of for warming. Hence advocates of drainage 
tell us that it lengthens the season. 

51. If a room is heated by an open fire, the radiant 
heat from the fire does not warm the air of the room, 
which can only be warmed by coming in contact with 
the walls and furniture that have been heated by the 
fire. Hence a grate or fire-place warms a room but 
slowly, and the fire may feel uncomfortably hot while 
the air of the room is yet cold. 

A stove radiates heat less rapidly than an open 
fire, but warms the air by convection. Hence an open 
fire is better for warming the walls and furniture of a 
room and so removing dampness ; but a stove warms 
the room more uniformly. 

52. The sun's rays pass through the air without 
communicating any warmth to it. The air is warmed 
only by contact with the soil. Hence the soil is often 
several degrees warmer than the air. 

53. Though gases allow radiant heat to pass 
through them readily, yet the minute particles of water 
suspended in the air will not. The partially con- 
densed vapor always present in the air prevents the 
heat that has been absorbed by the earth from being 
radiated off" into space. If it were not for this i)rotec- 
tion the earth would be uninhabitable. 

54. In the same way, and to a greater extent, 



HEAT AND ENERGY. 29 

clouds prevent the radiation of heat into space, and 
so in a cloudy night in fall and spring there is little 
risk of frost. Thus it is that the intensely cold nights 
of winter are usually those when there are no clouds 
and the air is very dry. 

55. In fruit-growing districts crops are often saved 
on nights when frost is threatened, by building fires 
that will produce a heavy mass of vapor and smoke 
that hangs like a cloud over orchards and vineyards. 
In some places arrangements have been made by the 
government weather stations by which warning of 
approaching frosts is sent to the fruit-growers who 
have their fires built ready to be lighted if needed. 



CHAPTER IV. 



CHEMISTRY. 

§ 1. Its Nature and Language. 

56. Chemistry treats of the composition of bodies, 
the changes that are occasioned by their combination, 
or the separation of those already combined, and the 
laws that control those changes. 

To understand chemistry, it is first necessary to 
learn something of the language and terms used. 

57. Chemical Combination. — The Avord combination 
in chemistry means something more than it does as 
usually employed. It indicates not only a bringing to- 
gether of certain substances, but such a union of those 
substances that their whole nature and character is 
changed. 

58. For example, quicklime is a white, caustic 
solid ; oil of vitriol is an oily liquid, intensely sour, 
and burns and corrodes whatever it touches. If 56 
lbs. of quicklime, 98 lbs. oil of vitriol and 18 lbs. of 
water are mixed, they will combine chemically and 
we will have 172 lbs. of land plaster, which bears 
scarcely any resemblance to the substances of which 
it was made. In this combination 116 lbs. of liquids 
were added to 56 lbs. of a solid and the result is a per- 
fectly dry solid. Thisjis the result of chemical com- 



CHEMISTRY. 31 

bination, which is entirely different from a simple 
mixture. 

The air we breathe is a mixture of two gases, but 
were those two gases to enter into chemical combina- 
tion, all life would iDorish from the earth. 

59. Chemic Force. — The power that causes sub- 
stances when brought together to enter into chemical 
combination is called chemism, or chemic force, or af- 
finity. The last term is however less used now. 

60. This force does not apply equally to all sub- 
stances — there are some that cannot be compelled to 
enter into chemical union at all, while others unite as 
soon as brought together. 

61. When two substances are united and a third 
is adde'd, it may disi)lace one of the others. Thus, if 
quicklime is exposed to the air, it will, in time, unite 
with the carbonic acid contained in the air, forming 
carbonate of lime. If to this vinegar is added, it will 
combine with the lime and set the carbonic acid free. 

62. Acids and Bases. — It would be impossible to ex- 
plain the strict chemical definition of these terms to 
the unscientific reader without devoting to it more 
space than can be given in this work. The statement 
that an acid is a compound of a non-metallic element 
with hydrogen and oxygen, and that a base is a com- 
pound of a metal with hydrogen and oxygen, is very 
nearly the scientific definition. 

In ;^opular language the term acid is applied to 
any substance that has a sour taste, and that readily 
enters into combination with the oxides of the metals, 
and a base is a metallic oxide. Both acids and bases 
in their ordinary condition contain the elements of 
water. 

63. Acids and alkalies are distinguished by the 



32 SCIENCE IN FARMING. 

fact that acids turn blue litmus paper red, and alka- 
lies restore the blue color. Litmus i^aper is made by 
soaking blotting paper in a solution of litmus and 
drying it. Litmus is a blue substance obtained from 
a lichen. Litmus paper is the common test to deter- 
mine wliether a substance is acid or alkaline. 

64. Exceptions. — Ammonia, which is not the oxide 
of a metal, possesses so distinctly all the character- 
istics of an alkali that it is universally recognized as 
such, and hydric chloride, though containing no oxy- 
gen, has all the properties of an acid, and is commonly 
known as muriatic acid. 

65. Salts. — Compounds produced by the union of 
an acid and a base. According to chemical lan- 
guage common table salt is not a salt. 

66. Solution. — When sugar is placed in water it 
gradually disappears, and we say it is dissolved. 
When finely powdered chalk is stirred up with w^ater 
it remains for a time mixed with, or suspended in the 
water ; but if the mixture is allowed to remain undis- 
turbed, the chalk will finally settle to the bottom. 
The first case is an instance of solution ; the second, 
of mixture or suspension. Kivers often carry, sus- 
pended in their waters, large quantities of mud and 
sand, and also, in solution, salts that have been ob- 
tained from the soil. 

67. A substance that will dissolve in water, such 
as salt or sugar, is called soluble. One that will not 
dissolve in water, such as sand or chalk, is called insol- 
uble. Many substances that are commonly called insol- 
uble, are really soluble, though only to a slight extent. 

68. Some substances will dissolve in one liquid 
but not in another. Common resin will not dissolve 
in water, but readily dissolves in alcohol. 



CHEMISTRY. 33 

69. Water containing; other substances in solu- 
tion will sometimes dissolve substances that are 
ordinarily insoluble. Thus water containing carbonic 
acid and certain organic acids will dissolve many sub- 
stances that are usually quite insoluble, and thus pre- 
sent them as food for plants. This is commonly the 
result of chemical action. Thus chalk will not dis- 
solve in pure water, but if vinegar is added, the 
chalk is dissolved. In this case the vinegar combines 
with the lime in the chalk, forming a soluble com- 
pound. 

70. Substances when not combined are called 
'^ free." Thus we speak of the free nitrogen of the 
air, and the combined nitrogen in albumin. 

71. Organic Substances. — Compounds that are pro- 
duced under the inlluence of animal or vegetable life, 
are called organic comi)ounds. Thus sugar, starch 
and gum are organic substances. So also are albu- 
min, fat, etc. In general, the term organic is applied 
to all animal and vegetable substances. 

§ 2. Chemical Laws. 

72. Combining Proportions. — Substances may be 
mixed together in all proportions, but chemical com- 
bination always takes place in fixed and definite pro- 
portions. This may be illustrated in three of the 
most common elements — carbon, oxygen and hydro- 
gen. Hydrogen and oxygen will combine by weight 
in the proportions : 

Oxygen 16 parts. 

Hvdrogen 2 parts. 

Or," 

Oxygen 32 parts. 

Hydrogen 2 parts. 

If 16 lbs. of oxygen were mixed with 3 lbs. of hy- 



34 SCIENCE IN FARMING. 

drogeii and the mixture caused to unite chemically, 
the oxygen would combine with 2 lbs. of the hydro- 
gen, forming 18 lbs. of water, and the 1 lb. of hydro- 
gen would be left uncombined. 

73. Carbon and oxygen will unite in the propor- 
tions : 

Carbon 12 parts, Oxygen .... 16 parts. 

Carbon 12 parts. Oxygen .... 32 parts. 

74. Carbon and hydrogen combine in numerous 

proportions, but they are all such as : 

Carbon 12 parts. Hydrogen 4 parts. 

Carbon 24 parts. Hydrogen 4 parts. 

Carbon 24 parts. Hydrogen 2 parts. 

It will be seen that in all these cases carbon enters 
into combination in the proportion of 12, 24, and so 
on ; hydrogen, 1, 2, 3, and so on, and oxygen, 16, 32, 
48, and so on. Every element lias some definite pro- 
portion in which it always enters into combination. 

75. Atomic Theory. — This property of matter is ex- 
plained by what is called the atomic theory. It is 
supposed that the atoms of which each element is 
comi)osed (18) are always of exactly the same weight, 
but that the atoms of different elements have different 
weights. When elements unite chemically, it is due 
to a union of the atoms. One atom of an element 
may combine with one, two, or more atoms of another 
element ; but as an atom is something that cannot be 
divided, it is impossible for atoms lo combine with 
fractions of atoms. 

76. If an atom of carbon weighed 12 ounces, and 
an atom of oxygen 16 ounces, and an atom of hydro- 
gen 1 ounce, it follows that a combination of oxygen 
and carbon must be in the proportion of 12 to 16, or 
12 to 32 ; that a combination of hydrogen and oxygen 
must be in the proportion of 1, or 2, or 3, or 4 of hy- 



CHEMISTRY. 35 

drogen to 16 or 32 of oxygen, and this is the case. 
We cannot know what is the actual weight of an 
atom, but the relative weights of the atoms of all the 
elements have been ascertained, and as the atom of 
hydrogen is the lightest of all, it is taken as the stan- 
dard, and the weight of the atom of an element, as 
compared with the weight of an atom of hydrogen, is 
called the atomic weight of that substance. And thus 
we say that the atomic weight of hydrogen is 1, of 
carbon 12 and of oxygen 16. 

77. Molecular Weight. — When the atoms of two or 
more elements combine, they form a compound atom 
called a molecule.* Of course the weight of this mol- 
ecule will be that of the combined weight of all the 
atoms of which it is composed. Thus carbon dioxide 
is composed of: 

1 atom carbon weighing 12 

2 atoms oxygen weighing 16 each 32 

Making 1 molecule carbonic dioxide weighing 44 

This is called the "molecular weight" of the com- 
pound. When compound bodies enter into combina- 
tion, they always do so in the proportion of their mol- 
ecular weight. Thus, the molecular weight of car- 
bonic dioxide, is as we have seen 44 ; that of calcic 
oxide (quicklime) 56, and when these two combine it 
will be in the proportion of 44 parts, by weight, car- 
bonic dioxide, and 56 parts, by weight, calcic oxide, 
forming 100 parts of calcic carbonate — or carbonate of 
lime. 

78. Equivalents. — In the older chemistries, the word 
equivalent was used to represent the same idea that 
is now represented by the words atom and molecule. 

*The word is derived from a Latin word meaning a little 
mass. 



36 SCIENCE m FARMING. 

Thus, carbonic dioxide was said to be comj^osed of one 
equivalent of carbon and two equivalents of oxygen, 
instead of one atom of carbon and two atoms of oxy- 
gen ; and calcic carbonate was said to be comi)osed of 
one equivalent of carbonic dioxide and one equivalent 
of lime instead of one molecule of carbonic diox- 
ide and one molecule of lime. The word equiva- 
lent was also used to represent atomic and mol- 
ecular weight. Thus it was said that the equiv- 
alent of carbon was 12, of carbonic dioxide 44, 
and so on. The term is about discarded, but is still 
occasionally seen. 

79. Application. — A knowledge of the atomic and 
molecular weight of bodies enables us to knoAV the 
proportions in which these substances are contained 
in their compounds. Thus we learn that tricalcic 
phosphate (commonly called bone phosphate) is com- 
posed of three molecules of lime, and one molecule of 
phosphoric acid. The molecular weight of lime is 
56, of iDhosphoric acid 142 (when in combination) so 
we know the composition of tricalcic phosi)hate to be : 

3 molecules lime weighing 56 each 168 

1 molecule phosphoric acid 142 

Making 1 molecule tricalcic phosphate 310 

And we know that the i^hospliate contains grfths of 
its weight of phosphoric acid. 

A knowledge of these facts also enables us to know 
in what proportion chemicals should be used to secure 
certain results. 

§ 3. Chemical Symbols and Formula. 

80. Symbols. — For convenience in representing the 
composition of bodies, chemists have adopted certain 
signs, each of which represents an element, and is 



CHEMISTRY. 37 

called its symbol. Usually the first letter of the name 
is used — thus C stands for carbon, O for oxygen, H for 
hydrogen. When the names of two elements begin with 
the same letter, the two first letters of one are used — 
as Ca for calcium. Sometimes the first letter of the 
Latin name of the element is used, as K for i)otas- 
sium, the Latin name of which is kalium. 

81. A compound is represented by writing together 
the symbols of all the elements it contains. Thus CO 
would represent a compound of carbon and oxy- 
gen. HSO a compound of hydrogen, sulphur and 
oxygen. 

82. The symbol not only represents the element, 
but exactly one atom of that element. Thus CO 
would represent a compound composed in the propor- 
tion of one atom of carbon and one atom of oxygen. 
When it is desired to represent more than one atom 
of an element, it is done by placing a small figure 
after the symbol and a little beloAV it. Thus CO 2 rep- 
resents a compound of one atom of carbon and two 
atoms of oxygen. The symbols representing the com- 
position of a substance are called its formula. Thus 
CO 2 is the formula of carbonic dioxide. Li this way 
the chemical composition of a substance can be stated 
with an accuracy, clearness and brevity not otherwise 
possible. When more than one molecule is to be rej)- 
resented, it is done by placing a large figure before 
the formula of that molecule, thus CaS042(H20) 
represents a compound containing one molecule of 
calcic sulphate, and two molecules of water. 

§ 4. The Elements. 

83. Of the sixty-three elements known to chemists 
agriculture deals with only fifteen. We give the list 
of these with their symbols and atomic weights : 



38 SCIENCE IN FARMING. 

Name. Symbol. Atomic Weight. 

Oxygen 16 

Hydrogen H 1 

Nitrogen N 14 

Chlorine CI 35.5 

Carbon C 12 

Phosphorus P 31 

Sulphur S 32 

Sihcon ; . . Si 28 

Potassium K* 39.1 

Sodium Nat 23 

Calcium Ca 40 

Magnesium Mg 24 

Aluminum Al 27.5 

Iron Fet 56 

Manganese Mn 55 

The first four are gases, the next four non-metallic 
solids, and the last seven metals. This being a work 
on agriculture, and only treating on chemistry so far 
as necessary to a comi)rehension of the science of 
farming, we devote no space to the other elements, 
and consider the fifteen named specially in view of 
their importance to the farmer. 

84. Oxygen. — A gas that forms about one-fifth of 
the atmosphere. It very readily unites with a great 
number of other substances. It was formerly called 
" vital air," as without it animals could not live and 
fires could not bum. Any substance that will burn 
in the air will burn more readily in this gas, and even 
substances that will not usually burn at all, such as a 
piece of iron wire, or a steel watch spring, will burn 
brilliantly in a jar of this gas. An animal when 
drowned dies from lack of oxygen, and fires are 
checked by excluding oxygen. An animal confined 
in the pure gas becomes excited and feverish, and 
soon dies from over excitement. Oxygen causes the 
decay of animal and vegetable substances, and with- 

^Frorn Kalium. tFrom Natrium. iFrom Ferrum. 



CHEMISTRY. 39 

out it fermentation and decay cannot take place. Fniit 
keeps in air-tight cans and ensilage in silos because 
the oxygen of the air is excluded. Though the pro- 
moter of fermentation and decay, it is also the great 
purifier, for where oxygen is supplied in abundance 
decay is rapidly carried so far that the material is re- 
duced to harmless forms. Oxygen is necessary not 
only for animal l)ut also for vegetable life. It is one 
of the most abundant of all elements, forming one- 
fifth of the atmosphere, eight-ninths of the water, and 
a large proportion of all rocks. 

85. Hydrogen. — The lightest known substance. A 
cubic foot of it weighs only one-sixteenth as much as 
a cubic foot of oxygen. It can be breathed Avithout 
injury, but an animal confined in the pure gas would 
die from lack of oxygen. It burns with a blue flame, 
and with air or oxygen gas forms a very explosive 
mixture. It is never found in nature except in com- 

"bination. 

86. Nitrogen. — This gas forms about four-fifths of 
the air. It will not burn, and though not i^oisonous 
an animal confined in the pure gas will die from lack 
of oxygen. It does not readily enter into combination 
with other elements, and except in the air is not 
abundant. It is an essential element however, in 
many organic substances. 

87. Chlorine. — A greenish yellow, heavy, poisonous 
gas, never found in a free state in nature. One of the 
elements of table salt. Used for bleaching and as a 
disinfectant. 

88. Carbon. — Well known in three forms : charcoal, 
black lead and diamond. The first two are nearly 
pure, the last perfectly pure carbon. Contained in 
nearly all organic* matter. It forms more compounds 



40 SCIENCE IN FARMING. 

than any other element. At ordinary temperatures 
it will not enter into combination with any other ele- 
ment, and is completely insoluble. When uncom- 
bined it is therefore without value as food for either 
plant or animal. When heated in the air it takes fire 
and burns, combining with the oxygen of the air to 
form carbonic dioxide — which readily enters into fur- 
ther combination and is the source from which the 
carbon in all its compounds is obtained. 

89. Phosphorus. — A waxy yellow substance that 
burns so readily it is usually kept under water. Used 
in commerce in the manufacture of friction matches. 
Combined with oxygen and hydrogen it forms phos- 
phoric acid, a substance of great agricultural imi)or- 
tance. 

90. Sulphur. — Well knoAvn as '' brimstone," or 
'' flowers of sulphur." It is contained in some organic 
substances. With oxygen and hydrogen it forms sul-^ 
phuric acid. 

91. Silicon. — A brown solid, known only in cbmbi- 
natiou. 

92. Potassium, Sodium, Calcium and Magnesium. — 
Metals known only in their compounds, which will 
be described in tlie next section. 

93. Aluminum. — A hard white metal of considera- 
l)]e value in the arts. In combination with silicon 
and oxygen it forms common clay. 

94. Iron. — In some form iron is necessary to the 
life of plants and animals. It forms two compounds 
with oxygen — one called the black oxide, the other 
the red oxide. Substances containing the first oxide 
are injurious to vegetation, and soils containing it are 
therefore unproductive. By exposure to the air the 



CHEMISTRY. 41 

black oxide is converted into the red oxide, which is 
of much vahie. 

85. Manganese. — A metal resembling iron, bnt of 
nnich less importance. Its compounds cannot take 
the place of those of iron in the soil. 
§ 5. The Compounds. 

96. In describing compounds we shall use tlie 

chemical symbols and formula, for the double reason 

that they can be more clearly and briefly represented 

in that way than in any other, and that it will be 

good practice for the student. It will be well for the 

student to refer to the table of atomic Aveights, and 

calculate for himself the proportion of each element 

contained in a compound. Thus we shall give the 

composition of sulphuric acid as H2SO4. A molecule 

of it is therefore composed of 

2 atoms of hydrogen, weighing 1 each 2 

1 atom of sulphur, weighing 32 

4 atoms of oxygen, weighing 16 each 64 

Making one molecule of sulphuric acid, weighing 98 

Sulphuric acid is therefore composed, by weight, of 
7y%ths hydrogen, f f ths sulphur, and ffths oxygen. 

The formula of starch w411 be given as CgHioOg. 
From this we learn a molecule of it contains 

6 atoms carbon, weighing 12 each 72 

10 atoms hydrogen, weighing 1 each 10 

5 atoms oxygen, weighing 16 each 80 

Making one molecule of starch, weighing 162 

Which shows the proportion of each element con- 
tained in starch. 

Suppose, for example, the reader wishes to know 
how many pounds of nitrogen are contained in a ton 
of sodic nitrate, commonly called nitrate of soda — a 



42 SCIENCE IN FARMING. 

popular fertilizer. Its formula is given as NaNOg. 

It is therefore composed of 

1 atom sodium, weighing 23 

1 atom nitrogen, weighing 14 

3 atoms oxygon, weigliing 16 each 48 

Making one molecule sodic nitrate, weighing 85 

A ton of it therefore contains i^ths of a ton of nitro- 
gen, and the number of pounds of nitrogen in a ton 
would be determined by multiplying 2000 (the num- 
ber of pounds in a ton) by the numerator of the frac- 
tion, and dividing by the denominator. Thus : 
A ton of pure nitrate of soda therefore 
contains 329|-| lbs. of nitrogen. 14 

97. Water.— H2O.Mol.Wt. 18.* AVa- ^^^ 

ter is the great natural solvent by q5)')S000('3'>9 
which plants and animals obtain their 255 

food. Its elements are also contained 

in a large number of organic and inor- 250 

ganic substances. It is commonly re- ' 

ferred to in four forms : water of combi- ^qq 

nation — as it exists in land plaster, 705 

which contains a little over one-fifth of — 

its weight of water in combination; '' hy- ^^ 

drostatic water," which means water 
that will flow out of the substance containing it, if 
opportunity is afforded ; capillary water, that which 
is retained within the pores of a substance and will 
not flow out, but is still perceptible to the senses; and 
hygroscopic water, that which is not perceptible to 
the senses, but can be driven out by heat. Nearly all 
substances that have been dried in the air contain 
hygroscopic water. 

^Henceforth we shall use the abreviation At. Wt. for atomic 
weight, and Mol. Wt. for molecular weight. 



CHEMISTRY. 43 

98. Ammonia. — Nn3. Mol. Wt. 17. A colorless gas, 
with a peculiar, pungent odor, often i)erceived about 
stables and manure heaps. It is very valuable as a fer- 
tilizer, and will be further considered in succeeding 
chapters. Being a gas, it readily escapes into the air 
and is lost. Water absorbs it readily, and a strong 
solution of it forms the " aqua ammonia," " spirits 
ammonia" of the drug stores. In this form it is val- 
uable in the household. It is useful in i^lace of soap, 
in cleaning paint, removing grease, etc. A little 
added to the water for the bath has a very refreshing 
effect. A few drops, given in water, makes an excel- 
lent stimulant in cases of fainting, i^oisoning, etc. A 
tea- spoonful added to a quart of water, is an excellent 
fertilizer for pot plants, but caution should be exer- 
cised not to use too much. It is often retailed at 5 or 
10 cents an ounce, but can be bought at wholesale at 
from 4 to 6 cents a pound. 

99. Carbonic Dioxide.— CO2. Mol.Wt. 44. Commonly 
called carbonic acid. A gas with a sour taste. About 
one-half heavier than the air, which contains about 
^^ig-(yth of its weight of this gas. When breathed in quan- 
tity it is highly poisonous, but the small amount 
present in the air is not injurious to animals, and is 
essential to vegetable life. It is given off in the 
breath of all animals, and by the fermentation or de- 
cay of organic matter. When wood or coal is burned, 
the carbon it contains unites with the oxygen of the 
air, producing this gas. Hence, if the smoke and gas 
from a fire are allowed to escape into a room, the air 
becomes poisonous. Lamps burning in a poorly ven- 
tilated room soon produce an injurious amount of this 
gas. It is the amount of this gas given off in the breath 
that makes the air grow foul in crowded rooms unless 



44 SCIENCE IN FARRMING. 

abundant ventilation is provided. Water absorbs 
this gas freely, and though poisonous when breathed, 
its solution in water is both palatable and wholesome. 
Spring water owes its sparkling to the presence of this 
gas. The water in the soil always contains this gas 
in solution. Water containing this gas will dissolve 
many substances not otherwise soluble, and thus pre- 
pare them for the food of plants. Hard water usually 
owes its hardness to limestone, which will dissolve in 
water containing cabonic acid, but not in pure water. 
As boiling the water drives off the gas, kettles in such 
regions of country soon become crusted with a coating 
of lime. Carbonic dioxide forms many compounds 
with bases, Avhich are called carbonates. 

100. Phosphoric Acid.— H3PO4. Mol. Wt. 98. This 
is really a compound of phosphoric pentoxide (P2O5) 
with three molecules of water, and is sometimes writ- 
ten thus: P2053(H20) Mol. Wt. 196. In its combi- 
nation with bases, one, two, or three molecules of 
water are replaced by one, two or three molecules of 
a base, and the compound is called a phosphate. 
Phosphates containing one molecule of base and two 
of water are distinguished by the prefix mono ; those 
containing two molecules of a base and one of water, 
by the prefix bi ; and those containing three molecules 
of base by the prefix tri. This will be more fully ex- 
plained later in this chapter. In analyses of foods 
and fertilizers, the term " Phosphoric acid " is used to 
represent P2O5, called by chemists phosphoric pent- 
oxide. 

101. Nitric Acid.— HNO3, Mol. Wt. 63. Known in 
the drug stores as " aqua fortis." It is formed to a 
small extent in the atmosphere by the direct combi- 
nation of its elements under the influence of electric- 



CHEMISTRY. . 45 

ity, and combines with the ammonia in the air, and is 
washed out by the rains. It is also formed to a consid- 
erable extent in the soil under certain circumstances 
by the oxidation of ammonia and organic substances 
containing nitrogen. Its compounds with bases are 
called nitrates. 

102. Sulphuric Acid.— H2SO4. Mol. Wt. 98. A 
heavy, oily liquid, commonly known as oil of vitriol. 
A pint weighs a little over 1| lb. It is very corrosive, 
burning and destroying most forms of organic matter. 
It should always be handled with great care. When 
mixed with water great heat is produced, and it is a 
dangerous experiment when incautiously done. In 
making the mixture, the acid should always be poured 
into the water, and never the water into the acid. It 
is usually sold in large glass vessels called carboys, 
and costs from 1\ to 3 cents a pound. Its compounds 
with bases are called sulphates. 

103. Silicic Dioxide.— SiO 2. Mol. Wt. 60. Com- 
monly called silica and sometimes silicic acid. It is 
commonly known as quartz, flint, etc. Nearly all 
rocks contain it. Water containing certain organic 
substances dissolves it to a small extent, and it is thus 
taken uj) by the plant with its food. Its compounds 
with bases are called silicates. 

104. Potassic Hydrate.— KHO. Mol. Wt. 56.1. An 
exceedingly caustic substance sold in the drug stores 
as caustic potash. It is always j)resent in good soils, 
and is essential to vegetable life. It is a large constit- 
uent in ashes, and gives them their value as a manure. 
It is contained in many rocks, which, by their decay, 
supply it to the soil. A mineral called kainit con- 
tains it in large quantities and is now extensively 
used as a fertilizer. The term '' potash," as used in 



46 ' SCIENCE IN FARMING. 

giving the analysis of foods and manures, means K2C>, 
called by chemists potassic monoxide, a substance 
usually known only in combination. 

105.' Sodic Hydrate .— NallO. Mol.Wt. 40. Caustic 
soda. It is used by plants to but a small extent, and 
cannot take the place of potash in the soil. 

106. Sodic Chloride.— NaCl. Mol. Wt. 58.5. Com- 
mon table salt. 

107. Calcic Oxide.— CaO. Mol. Wt. 56. Quicklime. 
Obtained by burning chalk or limestone, (calcic car- 
bonate.) This is a compound of lime and carbonic 
dioxide, and when exposed to heat the latter is driven 
off and the lime remains. Quicklime readily unites 
with water, forming slacked lime, with the formula 
H 2 CaO 2. When quicklime is exposed to the air, it 
gradually absorbs water and falls into a white powder 
— slacked lime. It also gradually absorbs carbonic 
dioxide and returns to its original condition of calcic 
carbonate. Hence, when lime is kept, it is necessary to 
exclude the air as much as possible. When applied 
to the soil it is very rapidly converted into carbonate 
of lime, but in a much finer powder than it could pos- 
sibly be reduced to by any other means. Lime is of 
value as food for plants, and it also has other proper- 
ties which will be more fully considered in the chap- 
ter on fertilizers. It has a strong " affinity" for all 
acids, and when mixed with a salt, will frequently 
coml)ine with the acid it contains and set free the 
base with which it had been previously combined. 
Thus, if sulphate of ammonia and quicklime are 
mixed, the result will be sulphate of lime and free 
ammonia, which, being a gas, will escape. Hence, 
lime should not usually be mixed with the manure 
heap. 



CHEMISTRY. 47 

§ 6. Comiiounds of Acids cmd Bases. 

108. Nitrates. — Nearly all the comi^ounds of nitric 
acid are soluble. The only ones of importance to the 
farmer are potassic nitrate, (KNO3, ^^ol. Wt. 101.1) 
commonly known as nitrate of potash, or saltpeter, 
and sodic nitrate, (NaNOg, Mol. Wt. 85,) commonly 
called nitrate of soda, or Chili saltpeter. 

Nitrate of potash occurs in abundance in the soils 
of some tropical countries, and is also produced arti- 
ficially in what are called " saltpeter plantations." 
Heaps of soil and organic matter containing nitrogen, 
are made, with lime or i^otash in some form, and left 
for many months to decomi)ose — being kept con- 
stantly moist. The nitrogen in the organic matter 
combines with oxygen from the air, forming nitric 
acid, which combines with the potash or lime in the 
soil, forming nitrate of potash or lime. This is after- 
Avards dissolved out by Avater, and when purified be- 
comes the saltpeter of commerce. It is too expensive 
for use as a fertilizer, but its formation naturally in 
the soil is a matter of great imj)ortance. 

Chili saltpeter derives its name from the fact that 
it is im]3orted in large quantities from South America. 
It is largely used as a fertilizer to supply nitrogen to 
the soil. It contains about fifteen per cent of nitrogen! 

109. Sulphates. — Calcic sulphate dihydrate, CaS04 
2(Tl2 0), is commonly known as gypsum, or land 
plaster. It is used as a manure, and furnishes both 
sulphuric acid and lime to the plant. The method of 
its action as a fertilizer is not well understood. When 
added to matter containing carbonate of ammonia, an 
exchange takes place — resulting in sulphate of ammo- 
nia and carbonate of lime. This makes it valuable 
for use in the manure heap and about stables to pre- 



48 SCIENCE IN FARMING. 

Yent waste of ammonia. When gypsnm is heated it 
parts with the two molecules of water, and is converted 
into calcic sulphate (CaS04) or plaster of Paris. 

Amnionic Sulphate, 2(NH4)S04, Mol. Wt. 132,— 
Suli)hate of ammonia. Largely used as a fertilizer 
on account of the large proportion of nitrogen it con- 
tains, amounting to about 21.2 per cent. 

Ferrous sulphate, commonly known as sulphate of 
iron, copperas, green vitriol. Valuable as a disin- 
fectant. When it is present in the soil in considera- 
ble quantity, it is poisonous to vegetation. The addi- 
tion of lime results in the formatiQu of carbonate of 
iron and suli)hate of lime. 

110. Phosphates. — The important compounds of 
phosphoric acid are those it forms with lime. 

Tricalcic phosphate, Ca3P208, Mol. Wt. 310. Bone 
phosphate. Forms about 55 per cent of all bones. Is 
also found in minerals called coprolite, apatite and 
phosiDliorite, of which there are large natural deposits 
in South Carolina, Canada, England, Spain, and some 
other countries. It is insoluble, and only available 
as plant food as it undergoes decomposition in the 
soil. 

Bicalcic phosphate, Ca2H2P208. Mol. Wt. 272. 
Obtained from the tricalcic phosphate by a process 
that will presently be described. Is slowly soluble, 
and can be used as food by plants. 

Monocalcic phosphate, CaH4P208. Mol. Wt. 234. 
Is readily soluble, and immediately available as i)lant 
food. 

HI. Preparation of Phosphates. — To understand the 
preparation of the bicalcic and monocalcic phosi)hates, 
it may be well to rej)resent their composition in this 
way — keeping in mind that phosphoric acid (using 



CHEMISTRY. 49 

that term to represent P2O5, called by chemists idIios- 
phoric pentoxide when not in combination) is usually 
in combination with 3 molecules of water, or some 
base. 

Tricalcic phosphate, CagPaOg, is equal to 

CaO) 

OaOV P2O5 

CaO) 
or three molecules of lime and one of phosphoric acid. 
Bicalcic phosphate may be represented 

CaO) 
CaOV P2O5 

or two molecules of lime, one of water, and one of 

phosphoric acid. 

Monocalcic phosphate may be represented 

CaO) 
H^O^ P2O, 

or one molecule of lime, two of water, and one of 
phosphoric acid. 

Sulphuric acid, H2SO4, may be represented 
H2O SO3. 

If we put together one molecule tricalcic phosphate 
one of sulphuric acid and two of water, they may 
be represented thus : 

1 Molecule 1 Molecule 2 Molecules 

Tricalcic Phosphate Sulphuric Acid Water. 



riaot p o ^^3 H2O 

^au> i: 2'-'5 HO HO 

CaO) ^2^^ ^2^ 
By re-arranging these we can get 



CaOV P2O5 CaOSOg jjj^^ 



H2O) 

4 



50 SCIENCE IN FARMING. 

By adding the elements under the first bracket, it 
will be found they constitute bicalcic phosphate, and 
by adding those under the second bracket, it will be 
found they constitute calcic sulphate dihydrate, and 
thus by mixing bone phosi^hate, sulphuric acid and 
water, we get, as the result of the chemical action, 
bicalcic phosphate and gypsum. 

If we add to the tricalcic phosphate double the pro- 
portion of sulphuric acid and water, the result will be 
one molecule of monocalcic phosphate and two mol- 
ecules of calcic sulphate dihydrate. The process of 
manufacture of the bicalcic and monocalcic phos- 
phate differs only in the amount of sulphuric acid 
and water used. The principle is the same in both 
cases. To aid the student in comprehending the prin- 
ciple, we will represent the process of making the 
monocalcic phosphate by words, instead of by symbols. 

One Molecule Two Molecules Four Mol- 

Tricalcic Phosphate. Sulphuric Acid. ecules Water. 

Phosphoric acid Sulphuric acid* Water 

Lime Sulphuric acid Water 

Lime Water Water 

Lime Water Water 

This gives us one molecule phosphoric acid, three of 

lime, two of sulphuric acid* and six of water. They 

can be re-arranged thus: 

One Molecule One Molecule One Molecule 

Monocalcic Phosphate Gypsum Gypsum 



Phosphoric acid Lime Lime 

Lime Sulphuric acid* Sulphuric acid* 

Water Water Water 

Water Water Water 

This subject is of importance because it explains the 



*Properly speaking, sulphuric oxide, SO 3, sulphuric acid 
being composed of one molecule sulphuric oxide combined with 
the elements of one molecule of water. 



CHEMISTRY. 51 

conversion of bones and rock phosphate into super- 
phosphate. The practical application, proportions 
needed, etc., will be given in the chapter on Fertilizers. 

112. Carbonates. — Carbonic dioxide is readily dis- 
placed from its compounds by other acids ; and car- 
bonates can usually be recognized by the fact that 
they boil up or effervesce when an acid is poured 
on them, the effervescence being caused by the escape 
of the carbonic dioxide in the form of gas. 

The carbonates that interest the farmer are calcic 
carbonate (carbonate of lime), and ammonic carbon- 
ate (carbonate of ammonia). Calcic carbonate is 
well known as chalk and limestone ; it is of some 
value in the soil. Soils that contain it in consider- 
able quantity are called calcareous, and may be rec- 
ognized by effervescing when vinegar or some other 
acid is poured on them. 

Ammonic carbonate is a white solid produced by 
the combination of ammonia and carbonic dioxide. 
It very readily passes into the form of vapor. It has 
the pungent odor of ammonia. As manure in decom- 
posing gives off carbonic dioxide as well as ammonia, 
the ammonia in manure usually exists in the form of 
carbonate unless some stronger acid is present to com- 
bine with the ammonia. 

113. Ammonic Chloride.— NH4 CI. Mol. Wt. 53.5. 
Commonly called sal ammoniac. It is used as a fer- 
tilizer to supply nitrogen of which it contains rather 
more than ammonic sulphate. 

§ 7. Organic Chemistry. 

114. Organic chemistry treats of those substances 
that are produced under the influence of animal or 
vegetable life. As these compounds all contain 



52 SCIENCE IN FARMING. 

carbon, this division of chemistry is frequently called 
the Chemistry of the Carbon Compounds. 

115. All organic substances are composed from the 
elements named on page 38 with the exception of sil- 
icon and aluminum. Silicon is not found in animal 
substances, and seems to be present in vegetable mat- 
ter rather as an accident than as an essential element ; 
and aluminum is not found in any form of organic 
matter. Besides these thirteen elements, very minute 
portions of a few others are sometimes found. 

116. Isomerism. — A large number of organic sub- 
stances are found to be composed of the same ele- 
ments, combined in the same proportion. Thus starch 
and cellulose, though quite unlike, are composed of 
the same elements combined in the same proportions. 
Such substances are said to be isomeric, and this par- 
ticular property can only be accounted for on the 
supposition of a dift'erent arrangement of atoms. 

117. Organic substances are divided into nitrogen- 
ous and non-nitrogenous. The non-nitrogenous com- 
prise the 

Carbohydrates, or amyloids ; 

The pectose group ; 

Fats ; 

Vegetable acids. 

The nitrogenous comprise the 

Albuminoids ; 

Amides ; 

Alkaloids. 

118. Carbohydrates are so called because they all 
contain hydrogen and oxygen in the proportion to 
form water. Many of them are isomeric. Most of 
them can be changed from one form to another, either 
— when isomeric, by a re- arrangement of their atoms, 



CHEMISTRY. 53 

or when not isomeric, by the addition or subtraction 
of the elements of water. 

119. Cellulose. O12H20O10, forms the solid sub- 
stance of most plants. It is not soluble in water but 
dissolves in weak acids. As the plant becomes older, 
another substance is deposited with the cellulose, 
called lignose, the exact chemical composition of 
which has not been ascertained, but which probably 
contains a larger proportion of carbon than cellulose. 
It is harder and less readily dissolved. 

120. Starch. CeHioOg.* This is contained in 
nearly all plants. It is insoluble in water, but read- 
ily changed into soluble substances, and hence is 
easily digested. Inulin is a modified form of starch 
found in some parts of plants. It is more readily 
soluble than starch. Dextrine has the same composi- 
tion as starch and inulin, but is readily soluble. Starch 
is converted into dextrine by the application of heat. 

121. Gums are a class of substances found in most 
plants. They are similar to starch in composition 
and general properties, but are mostly soluble. 

122. Sugars. There are quite a number of vege- 
table substances possessing the general characters of 
sugar, and difi'ering but little in composition. The 
most important are : cane sugar (sacharose) O12H22 
Oji; fruit sugar (laevulose) C6H12O6, and grape 
sugar (glucose) OgHiaOe.t Cane sugar is found in 

*The exact formula for these organic substances is not in all 
cases fully determined. Some authorities give starch as O12 
H2 0^1 • It will be observed that the proportions of the ele- 
ments are the same in either case. There is no question as to 
the percentage composition of these substances. 

tStrictly speaking, grape sugar is called dextrose, and the 
term glucose includes both Isevulose and dextrose, but in prac- 
tice the term glucose is principally used to describe dextrose 
artificially produced. 



54 , science'in farming. 

the juice of the sugar cane, in the sugar beet, and in 
many other plants. Fruit sugar is as sweet as cane 
sugar, but differs from it in that it does not granulate. 
It exists in honey and in many fruits. Grape sugar 
(glucose) has the same composition as fruit sugar, 
but differs from it in being only one-third as sweet. It 
can be granulated. 

Grape sugar differs in composition from starch only 
by the elements of a molecule of water. If we take 

* 1 molecule of starch Cq Hi q O5 

Add 1 molecule water H 2 Qi* 

We have 1 molecule glucose Cq H12 Qe 

As the proportionate weights of the molecules of 
starch and water are 162 and 18, it follows that if we 
could take 162 lbs. starch and 18 lbs. water and cause 
them to unite, we should have 180 lbs. glucose. 

By boiling starch or cellulose with water and an 
acid, it is caused to combine with the water, produc- 
ing glucose. The acid does not enter into the combi- 
nation, and at the close of the process remains un- 
changed in quantity and quality. The combination 
of the starch and water is effected by the presence of 
the acid, only. IIoio some substances thus induce 
changes in others by their presence is not understood. 
The property is called catalysis. 

Glucose is now made on a great scale, and used for 
adulteration of sugars and syrups and the manufac- 
ture of candies and alcohol. Starch, sulphuric acid 
and water are mixed in the proportions of 1,000 lbs. 
starch, 21 lbs. acid and 150 gallons water. The mix- 
ture is boiled until the starch has been converted into 

*When one atom of an element is intended, it is not usual to 
place the figure 1 after the symbol, as that stands for one atom. 
We do so in this case to make the addition more clear. 



CHEMISTRY. 65 

glucose. Chalk is then added, which combines with 
the acid, forming sulphate of lime or gypsum, which 
is separated by settling and straining. 

When pure, glucose is not unwholesome, but it is 
often carelessly made, and contaminated with the sul- 
phuric acid and chalk used in its manufacture. 

123. The Pectose Group. — These comprise a large 
number of substances that are found in i^lants and 
especially fruits. They are called pectin, pectose, 
pectic acid, etc. Their exact chemical composition 
has not been definitely determined, but they are not 
true carbohydrates, as the oxygen they contain bears 
a larger proportion to the hydrogen than it does in 
water. This group of substances forms the vegetable 
jellies — which differ from the animal jellies in not 
containing nitrogen, 

124. Vegetable Acids. — These are a very numerous 
class of substances, and differ from carbohydrates in 
containing a larger amount of oxygen. In analyses of 
foods, both the pectose group and the vegetable acids 
are frequently included in the estimate of the soluble 
carbohydrates. 

125. Fats. — The various oily, fatty and waxy sub- 
stances found in organic matter are divided into two 
classes: 'Volatile" oils, such as oil of peppermint, 
which give the fragrance to plant and flower, and 
which will evaporate like water ; and " fixed " oils, 
which will not evaporate, but leave a greasespot. The 
latter class are the only ones we need to consider in 
this work. 

Animal and vegetable fats are of the same gen- 
eral character, and consist principally of mixtures in 
varying proportions of three fatty principles : stearin 
— contained largely in tallow and the firmer fats; pal- 



56 SCIENCE IN FARMING. 

mitin, contained in palm oil, butter, beeswax, etc., 
and olein, which forms the liquid substance in fats 
and oils. The striking difference between fats and 
carbohydrates is the much larger proportion of carbon 
and hydrogen, and the much smaller proportion of 
oxygen contained in the fats. This is illustrated in 
the following table, giving the amount of each ele- 
ment contained in 10,000 parts of starch, pectin and 
olein : 

Starch Pectin Olein 

Carbon 4,444 4,067 7,740 

Hydrogen 617 508 1,180 

Oxygen 4,939 5,425 1,080 

10,000 10,000 10,000 

It will be remembered that starch fairly represents 
the carbohydrates, pectin the vegetable jellies, and 
olein the fats and oils. 

126. Albuminoids. — This term is applied to a large 
number of important substances, including all nitro- 
genous organic compounds except the amides and 
alkaloids. Most, if not all of them contain a small 
quantity of sulphur. Animal and vegetable albumin- 
oids differ but little in composition. Their exact 
chemical formula has not been positively determined, 
but their composition, in 10,000 parts, is about as fol- 
lows: 

Carbon 5,350 

Hydrogen 700 

Oxygen 2,240 

Nitrogen * 1,550 

Sulphur 160 

10,000 

By comparison with the table in paragraph 125, it 
will be seen that they contain a larger proportion of 
carbon and hydrogen than the carbohydrates and less 



CHEMISTRY. 57 

oxygen, holding an intermediate position between 
them and fats. 

127. Animal albumin is found nearly pure in the 
white of an egg. In its natural state it is soluble ; but 
heat, alcohol or acids change it into an insoluble 
form, or " coagulate" it. This is the change that 
takes place in cooking an egg. Musculine constitutes 
the substance of the muscles. Fibrine forms the "clot" 
in blood. Gelatine is obtained from the skin and 
bones of animals by the application of hot water. It 
is commonly seen in glue, and the finer and purer 
forms are sold as gelatine, isinglass, etc. Gluten is 
contained in wheat and most grains. It is not a sim- 
ple albuminoid, but a mixture of several. Keratin 
is the general name applied to the substances of 
which horn, hair and wool are formed. Animal 
casein is found in milk, and forms the substance of 
cheese. Vegetable casein, which closely resembles 
it, is found in peas, beans and other leguminous plants. 

128. Amides. — These vegetable nitrogenous com- 
pounds are not well understood. They exist princi- 
pally in roots and immature plants. In the plant 
they are convertible into albuminoids, but animals 
have not the power to effect this transformation. 

129. Alkaloids are a class of nitrogenous vegetable 
substances that exist in the plant in but small quan- 
tities. Tobacco owes its effects to an alkaloid called 
nicotine ; opium to an alkaloid called morphine ; tea 
and coffee derive their stimulating effects from an al- 
kaloid called theine, or caffeine. These substances, 
though of much general interest, are of little practical 
importance to the farmer. 

130. Transformation of Organic Substances. — The gen- 
eral similarity of organic substances renders their 



58 SCIENCE IN FARMING. 

change from one form into another very simple. In 
the natural laboratories of the plant and animal this 
is constantly being done. Carbohydrates are changed 
into each other, either by a re-arrangement oi 
their atoms, or by the addition or removal of the 
elements of water. By the removal of oxygen, carbo- 
hydrates are converted into fats, and fats again by 
the addition of oxygen, are changed back into carbo- 
hydrates. Out of carbohydrates and nitrates the 
plant manufactures albuminoids, and the animal can 
remove the nitrogen and part of the oxygen from the 
albuminoid and produce fat. These transformations 
will be more fully considered in the chapters on Plant 
Growth and Animal Life. 

§ 8. Coonbustion and Decay. 

131. The rapid union of any substance with the 
oxygen of the air, producing light and heat, is called 
combustion. In common language, it is said the sub- 
stance burns. The light and heat are produced by the 
union of the atoms of oxygen with the atoms of the 
substance, the force that had before been keeping them 
apart being converted into heat. Substances that will 
burn are called combustible ; those that will not are 
called incombustible. 

When a carbohydrate such as cellulose burns, the 
hydrogen and oxygen being in the proportions to form 
water, pass off as w^atery vapor, while the carbon 
combines with oxygen from the air, forming carbonic 
dioxide. As there are 12 atoms of carbon in a mol- 
ecule of cellulose, and as one atom of carbon unites 
with two atoms of oxygen in forming carbonic dioxide, 
it follows that in the combustion of a molecule of cellu- 
lose it unites with 24 atoms of oxygen from the air. 



CHEMISTRY. 59 

The process and its results may be thus shown: 

Cellulose Oxygen Result. 

&^ O i 12(00 J 

^20 '-'24^ 10(H2O) 

The student will quickly see that there are the 
same number of atoms of each element on each side 
of the brace. The proportions by weight would be 

1 molecule cellulose, weighing 324 

24 atoms oxygen, weighing 16 each 384 

Total material 708 

Resulting in 

12 molecules carbonic dioxide, weighing 44 each 528 

10 molecules water, 18 each 180 

Total product 708 

That is, when 324 parts of cellulose are burned, 
there is a combination of 144 parts of carbon with 384 
parts of oxygen ; or, when 1,000 lbs. of cellulose are 
burned, there is a union of 444 lbs. carbon with 1,269 
lbs. oxygen, making 1,713 lbs. of the two elements. 

When fat is burned, the proportions are somewhat 
different. Instead of the hydrogen and oxygen in the 
fat being in the proportion to form water, there is a 
great excess of hydrogen, so that not only does a 
thousand lbs. of fat contain more carbon than a thou- 
sand lbs. of cellulose, but when it burns, a large part 
of the hydrogen it contains also unites with oxygen 
from the air. In burning 1,000 lbs. olein, there would 
be a union of 

Carbon 771 lbs. 

Hydrogen 105 lbs. 

With oxygen 2,929 lbs. 

Total elements uniting 3,805 lbs. 

So that in the combustion of 1,000 lbs. of oil, the 
weight of the elements that enter into combination 



60 SCIENCE in'farming. 

is more than twice as great as in the combustion of 
1,000 lbs. of cellulose. Hence the much greater 
amount of heat produced. 

132. Decay. — When organic matters are exposed to 
warmth, air and moisture, the same chemical changes 
that take place rapidly in combustion, occur slowly, 
the result being the same in the end. This process of 
decay is called by chemists "eremacausis," which 
means slow combustion. During decay heat is pro- 
duced, as in combustion, but being developed much 
more slowly, is less noticeable. The products of 
the decay of non-nitrogenous organic matter are car- 
bonic dioxide and water. If the substance contains 
nitrogen, either nitric acid or ammonia will also be 
produced. 

The chemistry of respiration will be explained in 
the chapter on Animal Life. 



C H A P T E K V . 



SCIENCE IN AIR. 

§ 1. Its Composition and Characteristics, 

133. Composition. — The atmosphere is a mixture of 
oxygen and nitrogen, with a variable quantity of 
watery vapor, and a small amount of carbonic diox- 
ide. Its average composition, by weight, in 100,000 

parts is as follows : 

Nitrogen 78,492 

Oxygen 20,627 

Watery vapor 840 

Carbonic dioxide 41 

100,000 
This composition is commonly expressed as four parts 
nitrogen and one of oxygen. 

In addition to these substances the atmosphere al- 
ways contains a small amount of ammonia, dust, and 
other impurities. The proportions in which these 
exist are so minute that although their presence can 
be detected, it is extremely difficult to estimate the 

amount. 

134. The proportion of oxygen and nitrogen in the 

air in the open country never varies. In a close room 
where many persons are gathered, or in the crowded 
streets of large cities, the proportion of oxygen may 
be slightly reduced. The proportion of carbonic diox- 
ide is also nearly uniform except in places where 
from local influences this gas is produced more rapid- 



62 SCIENCE IN FARMING. 

ly than it can be diffused. The proportion of watery 
vapor varies greatly. It may be said therefore, that 
with the exception of water, the composition of the 
great bulk of the atmosphere is the same at all places 
and all seasons. 

The different gases of which the atmosphere is com- 
posed are simply mixed together, and are not in 
chemical combination (57). 

135. Diffusion of Gases. — If a jar containing hydro- 
gen is placed above one containing carbonic dioxide, 
and the two are connected by a small tube, the car- 
bonic dioxide gradually rises through the tube and 
diffuses itself through the hydrogen, which at the 
same time descends diffusing itself through the car- 
bonic dioxide, and although the latter gas is twenty 
times as heavy as the hydrogen this process will con- 
tinue — the heavy gas ascending and the light one de- 
scending, until both jars contain a mixture of the tw^o 
gases in exactly the same proportion. Whenever two 
gases are mixed, in any proportion, they will diffuse 
through each other until in time the composition of 
all parts of the mixture is the same. If the specific 
gravity* of one of the gases composing the mixture is 

*Specific gravity is the proportionate weight of a substance 
^-that is the relation that the weight of a given bulk of one 
substance bears to the weight of an equal bulk of some other 
substance taken as a standard. Thus a pint of oil weighs less 
than a pint of water, and so we say that the specific gravity of 
oil is less than that of water. A cubic foot of oxygen weighs 
more than a cubic foot of nitrogen, and we say that its specific 
gravity is greater. In practice, solids and liquids are com- 
pared with water as a standard, and gases with air. Thus the 
specific gravity of lead is 11.44, by which is meant that a given 
bulk of lead weighs eleven and forty-four one-hundredths times 
as much as an equal bulk of water. The specific gravity of 
hydrogen is .069, by which is meant that a given bulk of hydro- 
gen weighs sixty-ninQ one-thousandths as much as an equal 
bulk of air, 



SCIENCE IN AIR. 63 

greater than the other, more time will be required to 
eft'ect the diffusion, but it will be as thoroughly ef- 
fected. When different gases have thus been mixed, 
they do not again separate, however great may 
be the difference in specific gravity. This is called 
the Law of Diffusion of gases. 

It is this law that secures the uniformity of com- 
position of the atmosphere. Although the specific 
gravity of oxygen is greater than that of nitrogen, 
yet through the working of this law, the lower 
portions of the atmosphere contain no more oxygen 
than the upper portions. Although the specific grav- 
ity of carbonic dioxide is much greater than that of 
the other constituents of the atmosphere, yet it never 
separates, and settles into the low places and valleys, 
but the air on the highest mountain peaks contains 
as much as that at the level of the ocean. Owing to 
this law also, injurious gases poured into the air are 
soon diffused through the whole bulk of the atmos- 
phere, and by their great dilution become harmless. 
If it were not for this, cities would soon become unin- 
habitable by the accumulation of carbonic dioxide 
and other injurious gases, and every low place would 
be filled with poisonous gas. 

136. Apparent Exceptions. — Occasionally there is 
such an accumulation of carbonic dioxide in cellars, 
dry wells and old pits that persons entering them in- 
cautiously, lose their lives. In the island of Java 
there is said to be a place called the Valley of Poison, 
containing an accumulation of this gas. The ground 
is covered with the bones of animals which have 
been suffocated while passing through. These ex- 
ceptions are only apparent. In such cases the 
gas is being produced in the well, pit or valley, 



64 SCIENCE IN FARMING. 

more rapidly than it can be diffused through the air. 

When there is reason to suspect that carbonic diox- 
ide — or " choke damp," as it is x^opularly called, 
exists in dangerous quantities, a lighted candle should 
be lowered into it. If the gas is present in sufficient 
quantity to be dangerous the candle will be extin- 
guished. The best method of removing this gas from 
pits and cellars is by the use of quicklime. One 
hundred pounds of quicklime will absorb about 675 
cubic feet of the gas. 

The air near a large city contains a larger propor- 
tion of ammonia than that in the country, but this 
also is owing to the fact that the ammonia is produced 
in the city more rapidly than it can be spread through 
the surrounding atmosphere by diffusion. The winds 
assist in securing the uniform diffusion through the 
atmosphere of gases developed in special localities. 
§ 2. Importance of Each Constituent. 

No estimate can be made of the comparative value 
of the different constituents of the atmosphere, as each 
one is essential. 

137. Oxygen sustains life and combustion. It is 
essential to germination. It unites with organic mat- 
ter in the soil, giving rise to new compounds that can 
be used as food by plants. It combines with impuri- 
ties and poisonous gases in the atmosphere, changing 
them into harmless forms. It acts upon the rocks 
and rocky particles of the soil and reduces them to 
such a condition that plants can use them. It is 
the great purifier and disinfectant, as it converts dan- 
gerous organic compounds into harmless inorganic 
ones. Without oxygen neither plant nor animal 
could live ; and the action of oxygen on the soil is 
essential to maintain its fertility. 



SCIENCE IN AIR. 65 

138. The nitrogen of the air serves to dihite the 
oxygen, and prevent its too energetic action. Being 
itself perfectly harmless, and in many respects inert, 
it is excellently adapted for this purpose. Although 
it is essential to plant growth, the plant has no power 
to use the free nitrogen of the air ; it must be in com- 
bination with some other element before it can be ap- 
propriated by the plant. There is a probability that 
under certain circumstances the nitrogen of the air 
contained in the pores of the soil is oxidized and made 
available for plant food. The free nitrogen of the air 
is oxidized to a small extent through the influence of 
electricity, forming nitric acid, which combines with 
the ammonia in the air, forming nitrate of ammonia, 
which is washed out by the rains. The quantity 
supplied to the soil in this way varies, but probably 
the average does not exceed from 6 to 9 lbs. of nitro- 
gen per acre in a year, 

139. Although the proportion 'of carbonic dioxide 
in the atmosphere is small, (only one part in twenty- 
five hundred,) yet the volume of air is so great that 
the actual amount of this gas is very considerable. It 
is calculated the air over an acre of ground contains 
28 tons of this gas. This is a sufficient quantity to 
supply the needs of vegetation for many years, even 
were there no more produced ; but the processes of 
combustion, respiration and decay are constantly 
pouring this gas into the atmosphere.* 

The carbonic dioxide contained in the air supplies 
all the carbon for the plant. Careful experiments 
have shown that plants cannot grow and increase in 



*The amount of this gas absorbed by the leaves of plants 
equals that produced, and the balance is thus constantly main- 
tained. 
5 



66 SCIENCE m PARMlNa. 

weight in an atmosphere containing none of this gas. 
The constant motion of the winds causes an imnense 
amount of air to touch the leaves of plants, thus 
enabling them to obtain an abundant sui)ply of car- 
bon. The farmer, therefore, need have no anxiety 
about providing carbon or carbonaceous manures to 
the roots of plants. 

140. Water vapor is always present in the air, but 
the amount varies greatly. The warmer the air the 
greater amount of water it is able to retain. When 
the air contains all the water it can hold at that tem- 
perature, it is said to be saturated. When air that is 
partly saturated is cooled, a temperature will be 
reached at which it will be saturated, and any fur- 
ther decrease of temperature will cause the formation 
of mist or dew. The temperature at which ;iiist or dew 
begins to form is called the " dew point." Suppose 
the temperature of the air in a room was 70 degrees, 
and it contained enough water to saturate it at 60 de- 
grees ; if then the temperature was reduced to 60 de- 
grees, any further reduction would result in the form- 
ation of mist or dew, and 60 would be the dew point. 
The nearer the air is to saturation the closer will the 
dew point approach to the temperature of the air. 
Therefore a high dew point shows that the atmos- 
phere is nearly saturated. When a pitcher is filled 
with ice-water in summer, drops of dew soon begin to 
collect on the outside, and, in popular language the 
pitcher is said to '' sweat." The expression is incor- 
rect. The drops of water do not come through the 
pores of the pitcher, but the cold surface reduces 
the temperature of the air touching it below the dew 
point, and the water contained in the air is condensed 
on the sides of the j^pitcher. On a clear night the 



SCIENCE IN AIR. 6l 

leaves of plants, the surface of the soil and other ob- 
jects radiate into space the heat they have absorbed 
from the sun during the day. As soon as they are 
by this process cooled below the dew point, the mois- 
ture of the air is condensed on them, and we say the 
" dew falls." Strictly speaking, the dew does not fall, 
as it collects as readily on the under surface of an ob- 
ject as on its upper surface. As clouds check this 
radiation of heat into space (54), we rarely have dew 
on cloudy nights. 

141. As air is warmed, its capacity for water is in- 
creased, it feels dry, and will absorb water from what- 
ever it touches, although the actual amount contained 
is the same as before. This is the reason why the air 
of a " stove room" is injurious to the lungs, and de- 
structive to house plants, unless provision is made for 
increasing the amount of moisture in the air. 

The vapor of water in the air is not usually ab- 
sorbed by the plant, but an increase in the amount 
present refreshes the plant by checking evaporation 
from the leaves. The soil absorbs a considerable 
amount of moisture from the air, and in this way it 
becomes of use to the plant. 

142. The quantity of ammonia in the air is very 
small. A portion of this is absorbed directly by the 
leaves of plants, a portion is washed out by the rains, 
and a portion is absorbed by the soil. The amount of 
nitrogen brought down by the rains in nitric acid and 
ammonia has been given (138). What amount is 
absorbed by the leaves of plants and by the soil has 
not yet been determined, and varies so much under 
different circumstances, that it will be difficult to se- 
cure an average. The amount absorbed is greatly in- 
fluenced by the character and condition of the soil. 



68 SCIENCE IN FARMING. 

The source of ammonia in the air has not been pos- 
itively ascertained. Some of it is produced by the 
decomposition of organic matter ; some by the burn- 
ing of coal. There is always a larger amount brought 
down by rains in the neighborhood of cities than in 
country districts. 

§ 3. Summary. 

143. The farmer therefore gets from the air : 

Oxygen, to cause the germination of seed, the de- 
composition of organic matter, arid the reduction of 
the mineral portions of the soil to a form in which 
they can be used as food for plants. 

Nitrogen in the form of ammonia, absorbed by the 
leaves of plants and by the soil, and brought down by 
the rains, and in the form of nitric acid brought down 
by the rains. Also, probably, free nitrogen, to be ox- 
idized in the soil under proper conditions into nitric 
acid. 

Carbon, in the form of carbonic dioxide. The 
farmer can use the plant for the purpose of collecting 
carbon from the air and supplying it to the soil, for 
the improvement of its condition. 



CHAPTER VI. 



SCIENCE IN SOILS. 



§ 1. Origin of Soils. 

144. Soil consists of the broken fragments of rock 
mixed with partially decayed organic matter. The 
character of the soil, therefore, varies with the kind 
of rock from which it was produced, the extent of the 
decomposition it has undergone, and the kind and 
amount of organic matter that is mixed with the de- 
composed rock. 

145. Rock has been reduced to the condition of 
soil by various natural agencies. When the conti- 
nents were under the ocean, the force of the water 
broke oif fragments of rock, and by grinding these to- 
gether, reduced them to powder. During the ages 
when glaciers — great rivers of ice — covered much of 
the earth's surface, the rocks were ground to powder. 
After the continents took the form they now have, 
other agencies continued the work. Water penetrated 
the crevices of rock, and, freezing, broke and crum- 
bled it. It also gradually dissolved part of the rock. 
The air and water together caused the elements in 
the rock to separate and enter into new combinations. 
Thus by degrees a soil of inorganic material was 



70 SCIENCE IN FARMING. 

formed. The rains brought down and added to it ni- 
tric acid and ammonia from the air, and on this primi- 
tive soil low orders of plants, at first, began to grow; 
and as they decayed upon the soil, returned to it all 
they had gathered from both soil and air. Fresh sup- 
plies of nitrogen were constantly brought down by the 
rains, and this the vegetation changed into organic 
forms and restored to the soil again. Thus, through 
long ages, the wOrk of preparing the soil went on, 
and where the hand of man has not interfered, is still 
going on. 

§ 2. Composition and Classification of Soils. 

146. Soils are composed of three principal constit- 
uents — sand, clay, and humus. 

Sand is rock reduced to a powder. The composi- 
tion of each grain is that of the original rock. 

Clay is the product of the chemical decomposition 
of rock. When perfectly pure it is a silicate of alu- 
mina. It is seldom a pure silicate, however, usually 
containing potash, soda, magnesia, iron, and other 
substances. 

Humus is partially decayed organic matter. When 
organic matter reaches a certain stage of decay, it 
forms a dark colored mass, and decomposition pro- 
ceeds but slowly. This dark mass is humus. 

147. According to the proportion of these three in- 
gredients, soils are known as sandy, loamy, clayey 
and peats. 

Mixtures of sand and clay are usually classified 
thus: 



SOILS. 71 

Name of Per cent of Per cent of 

Soil. Sand. Clay. 

Sand 100 • 

Sandy loam 75 25 

Loam 50 50 

Clay loam 25 75 

Clay — 100 

Soils that do not exactly agree with any of these, 
are classed with the one to which they approach most 
closely. Thus, a soil containing 60 per cent sand 
and 40 per cent clay, or 60 per cent clay and 40 per 
cent sand, is called a loam ; while one containing 35 
per cent clay and 65 per cent sand is called a sandy 
loam, and one containing 35 per cent sand and 65 per 
cent clay, is called a clay loam. 

In swamps where a rank growth of vegetable mat- 
ter is produced every year, and decay is checked by 
excess of water, humus accumulates in great quantity, 
so that the soil consists almost entirely of partially 
decayed vegetable matter. Such soils are called peats 
or swamp muck. 

§ 3. Properties of Soils. 

The characteristics of soils* vary according to their 
chemical composition and their mechanical condition. 

148. Retention of Water. — If a portion of soil is 
soaked with water and then allowed to drain until 
no more will flow from it, a considerable amount of 
capillary water (97) will remain. Soils dilfer, not 
only in the amount of water they can retain within 
their pores, but also in the readiness with which they 
part with this water by evaporation. In the follow- 
ing table the first column of figures gives the number 
of pounds of water retained by 100 lbs. dry soil, and 
the second column the percentage of this water lost 



72 SCIENCE IN FARMING. 

by evaporation in a given time, the soils being all 
spread out and treated alike : 

Kind of Water Per cent lost by 

soil. retained evaporation. 

Quartz sand 25 88.4 

Clay loam 40 52 

Heavy clay 61 34.9 

Loam 51 45.7 

Garden mould 89 24.3 

Humus 181 25.5 

It will be seen that while pure sand retained only 
one-fourth of its weight of water, and lost nearly all 
of that by evaporation, in the short time (four hours) 
used in the exx^eriment, humus retained nearly dou- 
ble its Aveight, and lost but one-fourth of this by evap- 
oration in the same time. The retentive power of 
the garden mould was due to the large amount of hu- 
mus it contained. 

In general, it may be said that the larger the pro- 
portion of sand in a soil, the less power it has to 
retain water, and the more readily it will part by 
evaporation with what it contains ; and the larger the 
proportion of humus in the soil, the more water it 
will be able to retain aild the more slowly will it part 
with it by evaporation. 

The coarseness or fineness of the particles of a soil 
has a great influence on its power to retain water. 
The finer the particles, the more water it can retain. 
A very fine sand is greatly superior to a very coarse 
sand. 

149. Absorption of Water from Air. — Soils possess to 
a greater or less degree the power of absorbing mois- 
ture from the air. In this, as in the retention of wa- 
ter, soils diff'er greatly. The following table shows 
the number of pounds of water absorbed by 1,000 lbs. 



SOILS. 73 

of perfectly dry soil exposed to moist air for 24 hours, 
the result of one experiment : 



Quartz sand 

Heavy clay 41 

Garden mould 52 



Clay loam 28 

Loam 35 

Humus 120 



Sand, especially coarse sand, has little power of ab- 
sorbing moisture from the air. Clay has more power, 
and humus most of all. 

The amount of water absorbed from the air depends 
on the temperature ; the higher the temperature the 
less the absorption. The rapidity with which the ab- 
sorption takes place depends on the amount of mois- 
ture in the atmosphere. A given soil at a given tem- 
perature will absorb the same amount of water from 
the air, whether it contain a larger or smaller amount 
of moisture, but a longer time will be required in pro- 
portion to the dryness of the air. 

As a result of this property, soils — especially those 
rich in humus — that may become comparatively dry 
during a hot day, will absorb a considerable amount 
of water during the night. 

150. Capillary Attraction. — When a lamp-wick, or 
any other porous substance, is dipped into a liquid, 
the liquid will ascend through the pores of the sub- 
stance, and the force that causes it to ascend is called 
capillary attraction. The law governing the opera- 
tions of this force is that the smaller the pores of the 
substance, the greater hight the liquid will be raised. 
Soil being a porous substance, possesses the property 
of capillarity, to a greater or less degree, according to 
the number and fineness of the pores. In a soil com- 
posed largely of coarse sand, the pores are large and 
few, and the upper part of the soil may be quite dry 
while there may be abundance of water but a short 



74 SCIENCE IN FARMING. 

distance below the surface. A soil composed of fine 
particles contains a large number of small pores, and 
can draw water from considerable depths. Humus 
possesses this property in the highest degree ; coarse 
sand in the lowest. Soils composed of a mixture of 
fine sand, clay and humus, often possess it in a very 
high degree. 

151. Retention of Fertilizing Elements. — If the dark 
colored, offensive liquor from a manure heap is al- 
lowed to filter through a portion of good soil, the of- 
fensive and coloring matter will be retained by the 
soil, and the water that passes through will be free 
from color and odor. All soils possess this property 
to some degree, but certain soils possess it to a much 
greater degree than others. 

The effect is partly mechanical. The matters in so- 
lution adhere to the surface of the particles of the 
soil, and are thus retained. The more porous the soil, 
and the greater amount of surface is thus exposed to 
the liquid, the greater its power in this way. 

The effect is also partly chemical. Phosphoric acid, 
when in solution, unites with lime, alumina, and 
ferric oxide, forming insoluble compounds. Ammo- 
nia and potash enter into combination with the silica 
and alumina of clay soils, forming what are called dou- 
ble silicates. Calcic carbonate in some cases enables 
a soil to retain potash and ammonia. Humus has 
this retentive power in a great degree, acting both 
chemically and mechanically. 

In general, sandy soils have the least power of re- 
taining fertilizing elements, and the coarser the sand 
the less its power. Clay and humus have this power 
to a great degree. The power of clay is increased 
when it contains ferric oxide, the presence of which 



SOILS. 75 

can be recognized by the red color it imparts to 
the soil. 

152. Temperature of the Soil. — The warmth of the 
soil is derived from the rays of the sun, and is in- 
fluenced by the character and color of the soil and 
the amount of water it contains. 

Other things being equal, a dark soil absorbs 
warmth from the sun more rapidly than one of a 
lighter color (46). 

Sandy soil acquires heat more rapidly than a clay, 
as it is a better conductor (42), and the heat received 
from the sun is carried down into the soil. Such a 
soil, therefore, gains warmth more rapidly in the 
spring, and is also more likely to " burn out" during 
a hot season. 

A dry soil acquires heat more rapidly than a wet 
one, for the double reason that the specific heat (39) 
of water is much greater than that of soil, and that so 
large a portion of the heat received by a wet soil is 
expended in evaporating the water (34). It requires 
more than twenty times as much heat to raise the 
temperature of a wet soil to a point at which seed 
will germinate as would be required by a dry one. 
A well drained sandy loam, containing sufiicient hu- 
mus to make it dark in color, is best adapted to secure 
favorable results in temperature. 

153. Absorption of Ammonia. — The soil possesses 
the property of absorbing and condensing gases 
within its pores, and when exposed to the air 
under favorable conditions will absorb ammonia. 
If substances are present in the soil with which 
this ammonia can combine, the soil can then 
take up a further portion from the air. If the soil 
contains nothing to fix the ammonia, it is liable to be 



76 SCIENCE IN FARMING. 

again given off in the air and lost. Clay and humus 
possess to a greater degree than any other substance 
the property of absorbing and retaining ammonia. A 
moist soil absorbs more than one that is entirely dry. 
The rate of absorption depends on the amount of sur- 
face exposed to the air. 

154. Adhesiveness of Soils. — The common terms 
" light " and " heavy " as applied to soil, have refer- 
ence to its adhesiveness, or '' stickiness," and not to 
its actual weight. A cubic foot of pure sand weighs 
about 35 lbs. more than a cubic foot of clay, yet a 
sandy soil is called " light," and a clay soil " heavy." 
Clay is the most adhesive of all soils, and consequently 
the most difficult to work. The addition of sand re- 
duces its adhesiveness. Humus has the same effect. 

156. Weight of Soil. — The following table gives the 
weight of the dry soil on an acre taken to the depth 
of one foot : 

Sand '. 4,792,000 lbs. 

Loam 4,182,000 lbs. 

Common plow land 3,485,000 lbs. 

Heavy clay 3,267,000 lbs. 

Garden mould 3,049,000 lbs. 

Sand is the heaviest and humus the lightest con- 
stituent of soils, consequently those rich in humus, 
such as old pastures and rich black lands, weigh less 
to the acre than sandy or loamy soils. 

156. Wastes by Drainage. — The water that falls 
upon the soil and filters through it dissolves a portion 
of the soluble constituents, and analysis of drainage 
water shows that it contains nearly every element of 
fertility contained by the soil through which it has 
passed, with the exception of phosphoric acid. The 
amount of most substances removed by drainage is 
not,^^however, sufficient to be of practical importance. 



SOILS. , 77 

Most of the important soil constituents are retained 
in the manner already explained (151). Nitric acid 
is the important exception to this rule. Nearly all 
its salts being soluble it is freely carried away by the 
drainage water. The Nile pours 1,100 tons of salt- 
peter into the sea every 24 hours, the result of the 
drainage of the soil. 

About the only means by which the waste of 
nitrates by drainage can be prevented, is to keep the 
soil covered with a crop during the season when nitric 
acid is formed in the soil. The roots of the growing 
crops take up the nitrates as they are formed, and 
convert them into insoluble organic compounds. 

As will be seen (163), the nitrates are produced 
most rapidly during the warmer months. Cereal 
crops, wheat, etc., — leave the soil bare much of this 
time, and hence are exhaustive because they allow a 
waste of fertility. When clover is sown with wheat 
it remains after the latter has been cut, favors nitri- 
fication and saves the nitrates that are produced, by 
changing them into organic forms. 

§ 4. Chemical Characteristics of Soils. 

157. No two soils have exactly the same composi- 
tion chemically, and it would be difiicult even to get 
two samples of soil from different parts of the same 
field that would be exactly alike. All chemical anal- 
yses of soils are therefore approximate, only. 

The value of chemical analysis in determining the 
present fertility of a soil is but small. A soil may 
contain, as shown by analysis, an abundance of every 
element of plant food, and yet be unproductive, owing 
to the plant food being in insoluble combinations. A 
soil, however, that shows by analysis a large propor- 
tion of plant food, is usually one that can be made 



78 SCIENCE IN FARMING. 

productive by proper treatment. The following anal- 
ysis is of an excellent wheat soil : 

Silica 71.552 

Alumina . . . . : 6.935 

Ferric oxide 5.173 

Lime 1.229 

Magnesia 1.082 

Potash 0.354 

Soda 0.433 

Sulphuric acid 0.044 

Phosphoric acid 0.430 

Organic matter 10.198 

Water 2.684 

158. Plant Food. — The greater part of even the 

most fertile soils is of no value as plant food. Silica, 

though often found in plants, is not essential to their 

growth, and alumina does not enter the plant. Of 

the organic matter in the soil, only a small per 

cent is of value as plant food. It is necessary that a 

soil should contain all the elements found in the plant, 

except carbon, hydrogen and oxygen ; but as some of 

these elements are used by the plant in such minute 

quantity and are so universally present in the soil, 

they may in practice be disregarded. The substances 

usually considered as plant food are : 

Nitrogen Potash 

Phosphoric acid Lime* 

Sulphuric acid* 

An acre of the soil, the analysis of which has just 
been given, would weigh, taken to the depth of one 
foot, about 3,500,000 lbs., and would contain of these 
substances : 

Nitrogen (probably) 8,000 lbs. 

Phosphoric acid 15,050 lbs. 

Sulphuric acid 1 ,540 lbs. 

Potash 12,390 lbs. 

Lime , 43,015 lbs. 



*Lime and sulphuric acid are usually present in sufficient 



SOILS. 79 

Few soils are as rich in phosphoric acid as the one 
above given, and many are much richer in sulphuric 
acid. 

159. Exhaustion of Soils. — When crops are contin- 
uously grown and carried away, nothing being re- 
turned to the soil, the amount of plant food undergoes 
a steady diminution. A crop of 30 bushels of wheat 
and the straw will take from tlie land, of 

Nitrogen 45 lbs. 

Phosphoric acid 22.7 lbs. 

Sulphuric acid 10.5 lbs. 

Potash '. 27.9 lbs. 

Lime 10.2 lbs. 

If a crop of 30 bushels of wheat to the acre were 
grown every year, and both grain and straw carried 
away, nothing being restored to the land, it would ex- 
haust the soil, the analysis of which has just been 
given, of these constituents as follows : 

Of nitrogen in 177 years. 

Of phosphoric acid in 766 years. 

Of sulphuric acid in SO years. 

Of potash in 444 years. 

Of lime in 4,217 years. 

Practically it would be impossible to exhaust the 
soil of these substances, as, before it was exhausted, 
crops would cease to grow. 

160. Eotation. — The exhaustion of the soil by a ro- 
tation of crops, especially where a large portion of the 
crop is fed on the farm, is much slower. Take, for 
illustration, a farm of eighty acres. Suppose that the 
crops grown are Indian corn, wheat, clover and grass; 
that such a rotation is adopted that twenty acres 
are each year devoted to each crop. SuiDpose nothing 

quantity, and are therfore frequently disregarded in estimating 
the quality and needs of soils. 



80 SCIENCE m FARMING. 

is sold but wheat and animal products. "We will esti- 
mate the annual average crops to be, 

Wheat (400 bushels) 24,000 lbs. 

Straw 48,000 lbs. 

Clover hav 100,000 lbs. 

Hay. . . . ; 80,000 lbs. 

Corn (1,000 bushels) 56,000 lbs. 

Corn fodder 168,000 lbs. 

Calculating that in feeding the straw, hay, corn, 
and fodder, 10 per cent of the nitrogen, phosphoric 
acid and potash are taken by the animal, and 90 per 
cent returned in the manure, the loss of these constit- 
uents each year would be: 

Nitrogen. Phosphoric Acid Potash. 

Wheat* 440 lbs. 191 lbs. 129 lbs. 

Strawt 23 lbs. 12 lbs. 29 lbs. 

Clovert 197 lbs. 56 lbs. 195 lbs. 

Hayt 124 lbs. 30 lbs. 134 lbs. 

Cornt 93 lbs. 34 lbs. 20 lbs. 

Cornfoddert 80 lbs. 89 lbs. 161 lbs. 

Total loss 957 lbs. 412 lbs. 668 lbs. 

Dividing these amounts by 80 — the number of acres 
— we get the loss per acre per annum on a farm so con- 
ducted : 

Nitrogen _ 11.96 lbs. 

Phosphoric acid 5.15 lbs. 

Potash 8.35 lbs. 

With this rotation, it would require, to exhaust the 
soil described in paragraph 158 : 

Of nitrogen 668 years. 

Of phosphoric acid 2,922 years. 

Of potash 1,484 years. 

Under a proper rotation there need therefore be no 
apprehension of exhausting, or even of materially re- 
ducing, the amount of plant food in a fertile soil in 
any ordinary life time. In fact, except by allowing 

^Amount contained in entire crop, t One-tenth amount con- 
tained in entire crop. 



SOILS. Sf 

it to wash away, it would be impossible to exhaust 
the plant food in any fertile soil in a hundred years. 

161. Condition of Plant Food in Soil. — The greater 
part of the plant food in the soil exists in forms of 
combination that cannot be used by the plant until 
they have undergone some chemical change. The 
same causes that prevent the exhaustion of the plant 
food by drainage, also prevent it from being imme- 
diately used by a crop. Nitrogen usually exists in in- 
soluble organic compounds ; phosphoric acid in insolu- 
ble phosphates of lime or iron ; potash in combination 
with silica and alumina. A soil may contain enough of 
these constituents to produce 30 bushels of wheat per 
acre for five hundred years, and yet not contain 
enough of them in a form the i3lant can use to pro- 
duce a single crop of 10 bushels to the acre. Some 
soils that are called " exhausted " or " run down " 
contain a great deal more plant food in an acre than 
others that are called extremely fertile. In the one 
case the plant food is available, in the other it is not. 
A large part of the science of farming consists in 
knowing how to render the plant food in the soil 
available, and how to secure it with a crop before it 
is wasted by drainage. 

162. Chemical Changes in the Soil. — In order that 
the plant food in the soil may be rendered available, 
chemical action must be constantly maintained. The 
principal agents by which the chemical changes are 
effected, are the oxygen of the air, and the carbonic 
dioxide in the water of the soil. 

By the action of the carbonic dioxide, the tricalcic 
phosphate is gradually changed into bicalcic phos- 
phate, the nature of the change being similar to that 
described on page 49, carbonic dioxide taking the 



8^ SCIENCE IN EARMING. 

place of sulphuric acid. The same agency also 
changes the potash into a soluble form. 

By the action of the oxygen of the air, the organic 
matter in the soil is changed into ammonia, water, 
and carljonic dioxide — and the ammonia is also 
oxydized producing nitric acid and water. 

163. Nitrification. — By this is meant the conversion 
of the nitrogen contained in organic matters and am- 
monia into nitric acid. It is one of the most impor- 
tant chemical operations in the soil — as it is in the 
form of nitric acid — or its compounds with bases — 
that nitrogen becomes available for the use of a crop. 
The conditions necessary for nitrification are : 

A porous soil. 

The presence of the carbonates of potash, lime or 
soda in the soil. 

Warmth. 

Moisture. 

Under these conditions and through the influence 
of a minute fungus plant called bacterium^ the nitro- 
gen of the organic compounds unites with the oxygen 
of the air, producing nitric acid, which as rapidly as 
formed combines with the lime, potash or soda pres- 
ent, forming nitrates. 

Nitrification proceeds more rapidly the higher the 
temperature, and ceases altogether at the freezing 
point. When the soil contains an excess of water, 
nitrification ceases, and nitrates are sometimes decom- 
posed with the escape of free nitrogen. 

In order that nitrification may proceed rapidly and 
keep the growing crop supplied with available nitro- 
gen, it is necessary that the soil be kept porous so 
that it presents a large amount of surface to the air, 
and that it be moist but not wet. These conditions 



SOILS. 83 

are secured by drainage and cultivation. Mulching 
the ground favors nitrification by keeping the soil in 
a moist, porous condition. Part of the value of clover 
and other crops that shade and cover the ground is 
due to the fact that they thus provide the conditions 
favorable for nitrification. 

§ 5. Mechanical Conditions of Soils. 

164. Effects of Division. — A cube 1 inch each way, 
has 6 square inches surface. If it is divided once in 
each direction, and reduced to 8 cubes, each ^ inch 
each way, these smaller cubes will have 1| square 
inches surface — or 12 square inches in all. By the di- 
vision the total amount of surface has been doubled. 
If the division is continued until the original cube has 
been divided into a million cubes, the surface will be 
increased six hundred times. Thus the smaller the 
particles of the soil, the greater the amount of surface 
will be exposed to the air which penetrates it, to the 
water, and to the roots of plants. 

The retention of water and of fertilizing material is 
due largely to adhesion to the surface of the particles 
of the soil; hence the smaller these particles the 
greater the amount of this retention. The absorption 
of moisture and ammonia from the air is in propor- 
tion to the surface exposed. The chemical action of 
air upon the soil is in proportion to the amount of 
surface exposed. The smaller the particles of soil the 
smaller and more numerous will be the pores, and 
hence the greater will be its capillarity. 

For all these reasons, the fertility of the soil de- 
pends greatly on the fineness of its particles, and soil 
that in its ordinary condition is almost sterile is some- 
times rendered quite productive by thorough pulver- 
ization. 



84 SCIENCE IN FARMING. 

165. Some soils, especially heavy clays, are so com- 
pact that the air cannot penetrate them, and the roots 
of plants find difficulty in doing so. Such soils " bake" 
into compact masses, and in that condition they are 
of little value. It is necessary to mix sand or hu- 
mus with such soils to make them sufficiently open 
and porous to admit the air, and to separate their 
particles so as to prevent " baking." 

166. Drainage. — Soil may contain water in three 
conditions: hygroscopic, capillary, and hydrostatic 
(97). When it contains hydrostatic water the parti- 
cles of the soil are wet, and the pores between them 
are filled with water. The water prevents the air from 
I)enetrating the soil, and renders it unfit for the growth 
of agricultural plants,* and the chemical changes nec- 
cessary to make the plant food in the soil available can 
not take place. 

167. When soil containing hydrostatic water dries, 
it shrinks and hardens into compact masses. The 
shrinkage causes the soil to crack, often breaking the 
roots of plants. This is particularly the case with 
clay soils. The compact masses thus formed ofter 
great resistance to the roots of plants, and as they can 
not readily be penetrated by the air, but little mois- 
ture can be absorbed from it. The cracks caused by 
the shrinkage are too large to favor capillary attrac- 
tion, and moisture is not drawn up from below. 

Water falling on soil in such a condition is absorbed 
slowly, and much of it may flow off, leaving the 

*The term "agricultural plants" is used to describe those 
which are cultivated by the farmer. There are some others 
which grow under very different circumstances and obtain 
their food in a different manner, such as aquatics, (plants which 
grow in water), parasites, (those which grow on others), and 
funjj-i. 



SOILS. 85 

ground at the depth of a few inches unmoistened. 
Therefore an undrained soil, particularly if it be a 
heavy clay, suffers greatly in a drought. 

168. When, by means of ditches or underdrains, 
the hydrostatic water is removed, the soil remains 
moist, as the capillary water cannot thus be removed. 
The roots of plants find sufficient moisture in the par- 
ticles of the soil, and as the pores are filled with air, 
this supplies the oxygen necessary for their growth 
and health. 

When a well drained soil becomes dry, it does not 
harden into compact masses, nor shrink and crack, 
but remains in a loose and porous condition. During 
the night the temperature of the soil is reduced by 
I'adiation, (44), and moisture is condensed from the 
air. If the soil is compact and impervious to air, this 
moisture will be condensed upon the surface only ; 
but if by drainage it has been left porous, the mois- 
ture will also be condensed within its pores, often to 
a considerable depth. Drainage also favors capillary 
attraction in the soil, thus enabling it to draw water 
from below. A light rain falling on such a soil is im- 
mediately absorbed. For these reasons drainage ena- 
bles the soil to withstand drought. 

A loose, porous soil presents to the air many times 
as much surface as a hard and compact one, thus se- 
curing a larger absorption of ammonia, and providing 
conditions favorable for nitrification (163). In this 
way drainage increases the fertility of the soil. 

In some parts of Minnesota the soil consists of a 
deep sandy loam, containing a large amount of hu- 
mus. The sand is exceedingly fine. This soil seems 
of almost inexhaustible fertility. It is moist a few 
Inches beneath the surface during the dryest weather, 



86 SCIENCE IN FARMING. 

and can be worked immediately after the heaviest 

rain. 

§ 6. Valne of Sand, Clay and Humus. 

169. Sand. — The value of sand in the soil depends 
on the kind of rock from which it has been reduced, 
and the size of its particles. White quartz sand con- 
tains no plant food, and soils containing it in large 
quantity are not usually fertile. 

To determine the character of the sand, mix a por- 
tion of the soil with a large amount of water. After 
allowing time for the sand to settle, pour off the wa- 
ter, which will contain most of the clay and humus. 
By repeatedly washing the sand which remains, it 
may be obtained pure. If it is white, " sharp" and 
coarse, it is of little value in the soil. Sand from 
granite or limestone contains a considerable amount 
of plant food, which, under the influence of air 
and cultivation, will be slowly given up in avail- 
able form for the plant. If the portion of soil used in 
the experiment is first dried and weighed, and the 
sand that remains also dried and weighed, the propor- 
tion of sand in the soil will be known. 

The mechanical uses of sand in the soil are to make 
it loose and porous, facilitate drainage and prevent 
" baking." Sand alone does not absorb moisture or 
ammonia from the atmosphere, nor has it the power 
of retaining plant food. Manures applied to sand 
have little efi'ect beyond the immediate crop. Sand 
becomes warm early in the spring, and soils contain- 
ing it in excess are liable to . " burn out" in hot wea- 
ther. When mixed with a due proportion of clay and 
humus, the advantages of sand are secured without 
its disadvantages. The finer the sand the more value 
it is in the soil. 



SOILS. 87 

170. Clay. — Pure silicate of alumina (146), sup- 
plies no food to the plant, but clay in the soil usually 
contains potash, magnesia, lime, and other substances 
of value. Red clays contain ferric oxide, valuable 
not only as plant food, but also because it promotes 
nitrification and aids in retaining nitrates in the soil. 

Clay possesses, in a high degree, the properties of 
absorbing ammonia from the air, and of retaining fer- 
*tilizers. Lime, potash and ammonia combine with it, 
firming double silicates. Clay thus not only absorbs 
ammonia from the air, but retains it when absorbed 
(153). It has also in a considerable degree the power 
of retaining water, of absorbing moisture from the air, 
and of capillarity. 

Clay soils are called " retentive." Manures applied 
to them waste but little, and often continue to pro- 
duce marked effects for years. 

The disadvantages of clay are its adhesiveness, mak- 
ing it a " heavy" soil to work, and its tendency to 
"bake." The addition of lime renders it less adhe- 
sive, the fine particles of calcic carbonate formed in 
the soil, separating the particles of clay. Burn- 
ing clay entirely destroys its adhesiveness, and if the 
burnt clay is mixed with the soil, it has an efi"ect similar 
to the addition of sand. This plan is sometimes re- 
sorted to in dealing with very " stubborn" clay lands. 

171. Humus (146). — The proportion of humus in 
the soil varies from 2 or 3 per cent to as much as 97. 
To ascertain the per cent of humus, weigh a portion 
of the soil that has been thoroughly dried in an oven, 
and heat it to a dull redness, until all the organic 
matter is consumed. Weigh what remains, and the 
loss in weight will show the amount of humus. 

Humus contains carbon, hydrogen and oxygen, but 



88 SCIENCE IN FARMING. 

the plant does not obtain these from this source. It 
also contains nitrogen in organic combination, which 
cannot be directly used by the plant, but which is 
gradually converted into ammonia and nitric acid by 
the action of the air. The amount of nitrogen con- 
tained in a soil is usually in proportion to the amount 
of humus it contains. Humus also contains some 
phosphoric acid, potash, and other mineral elements 
of plant food. * • 

Humus has other value in the soil besides suppl- 
ing plant food. Its dark color makes the soil warmer. 
It has great power of retaining water and of absorbing 
moisture and ammonia from the air. Being very 
porous it possesses capillarity in a greater degree than 
any other soil constituent. The decomposition of 
humus in the soil produces carbonic dioxide which, 
being dissolved in the water of the soil, assists in the 
decomposition and solution of mineral matters. 

Humus overcomes the adhesiveness of clay soils, 
and remedies the deficiencies of sand. 

The addition of lime to humus hastens its decom- 
position by favoring the conversion of the nitrogen it 
contains into nitric acid. 

§ 7. Practical Application. 

172. The soil best adapted for most agricultural 
purposes is composed of fine sand, clay and humus. 
No one of these ingredients should be in great excess. 

173. Correcting Defects in Soil. — Soils may be good 
in many respects and contain an abundance of most 
of the elements of plant food, and yet from deficiency 
of some one constituent, or defective mechanical con- 
dition, be unproductive. Such soils may often be 
rendered valuable at moderate expense by proper 
treatment, which can be determined by a considera- 



\ 



SOILS. 89 

tion of their character and of the principles already 
given. 

174. A soil may contain an excess of humus and 
yet be unproductive. The plan to pursue is to secure 
the decomposition of the humus, and the conversion 
of the plant food it contains into available forms. 
This can be accomplished by drainage and thorough 
cultivation, by which the soil is exposed to the air, 
and by the addition of lime. Soils of this kind are 
sometimes " sour " owing to the presence of organic 
acids produced by the slow decomposition of humus, 
and which are injurious to plants. Lime combines 
with- these acids forming harmless compounds. The 
addition of phosphates or potash may sometimes be 
beneficial.* When phosphates are needed, rock 
phosphate — which contains no nitrogen — would be 
suitable, as the soil already contains an abundance of 
nitrogen which only needs to be rendered available. 
Green manuring on such a soil would be injurious 
rather than beneficial . 

175. A sandy " leachy " soil may be improved by 
growing a succession of green crops, rye, buckwheat, 
sowed corn, clover, etc., and plowing them under. 
The humus thus furnished will supply those charac- 
teristics of the soil lacking in the sand. Nitrogenous 
manures may be used with profit, but they should be 
applied on the surface and at the season when the 
plant can make immediate use of them. After a suf- 

*Whether phosphate and potash are needed can only be de- 
termined by experiment. Four portions of the field should be 
marked off. To one portion phosphate should be applied, to 
another potash, to the third both, and the fourth should re- 
ceive no manure. The cultivation, drainage and liming of the 
four portions should be the same, and the results carefully 
noted. 



90 SCIENCE IN FARMING. 

ficient amount of humus has accumulated in the soil, 
the crops may be fed off and the manure produced 
returned. 

176. A " retentive" clay is often a difficult soil to 
deal with, but can usually be rendered valuable by 
proper treatment, and as it has great capacity for 
retaining manures, those which are applied and not 
immediately used by the crop will accumulate in the 
soil. The first treatment indicated is thorough drain- 
age — which will make the next step — thorough culti- 
vation, possible. The adhesiveness may be x)vercome 
by the use of lime, by plowing under long barn-yard 
manure, and by green manuring. Nitrogenous 
manures, such as bone phosphates and guano can be 
used with advantage — but should not be applied at 
the same time with the lime, or a waste of nitrogen 
may be occasioned. After the condition of the clay 
has been sufficiently improved, the plowing under of 
green crops may be discontinued. 

177. Thus by drainage, cultivation, green manur- 
ing and the use of lime, the farmer can to a great ex- 
tent remedy natural deficiencies in the soil. Of the 
three great soil constituents, humus is the only one 
over which control can be exercised. By the use of 
lime and cultivation it can be reduced in quantity 
when in excess ; and by plowing under green crops 
it can be increased when needed. 



CHAPTER VII. 



SCIENCE m PLANT GROWTH. 



§ 1. Composition of Plants. 

178. Water. — The largest constituent of all living 
plants is water. The following table gives the aver- 
age percentage of water in various fresh plants : 

Meadow grass 72 

Red clover 79 

Corn fodder 81 

Cabbage 90 

Potatos (tubers) 75 

Beets 82 

Turnips 91 

Pumpkins 94.5 

The per cent of water is not always the same. It 
is greater in plants grown in a wet season than in 
those grown in a dry one. The ranker the growth 
of plants the more water they contain, hence the in- 
creased weight of crop caused by heavy manuring is 
often chiefly water. In some cases the amount of dry 
matter contained in a crop grown on a manured soil 
may be less than that in a crop produced without 
manure. The following table gives the weight (fresh 
and dried) of two crops of clover grown on an acre of 
ground each, one with, and one without manure. 

Fresh Clover. Clover Hay. 

Manured acre 22,256 lbs. 4,800 lbs. 

Unmanured acre 18,815 lbs. 5,190 lbs. 



92 SCIENCE IN FARMING. 

It will be seen that while the crop on the manured 
acre was ranker and weighed more when fresh than 
that on the unmanured acre, it contained so much 
more water that the amount of hay was less. 

179. Even dried plants and the seeds and grains 
contain a considerable amount of hygroscopic water 
(97). The following table gives the per cent of water 
contained in various plants and grains that are usually 
considered dry : 

Meadow hay 15 

Glover hay 17 

Straw 15 

Wheat (grain) 14 

Indian corn (grain) 12 

Wheat bran 14 

The amount of hygroscopic water varies a little 
with the temperature and the condition of the atmos- 
phere. 

The term " dry substance " is used to describe all 
the plant except the water. Thus, fresh meadow 
grass contains about 28 per cent dry substance; 
meadow hay 85 per cent ; Indian corn 88 per cent, 
and so on. That is, 100 lbs. meadow grass if dried at 
a temperature of 212, so as to drive off all the water 
would weigh 15 lbs.; 100 lbs. Indian corn would 
weigh after being dried in this manner 88 lbs. As the 
quantity of water in different plants varies so greatly 
it is often necessary in making comparisons to con- 
sider only the dry substance each contains. 

180. Ash. — When a plant is burned, part passes off 
in gas and vapor, but a part remains unconsumed. 
This is called the ash, and the amount of it varies in 
different plants, and in the same plants grown under 
different circumstances. Plants grown on a soil rich 
in available ash cpiistituents will contain more^ash 



PLANT GROWTH. 93 

than the same plants grown on soil in which these 
substances are deficient. The following table gives 
the percentage of ash in the dry substance of various 
plants : 

Wheat (grain) 2 

Oats (grain) 3.3 

Indian corn (grain) 1-5 

Timothy 7.1 

Red clover 6.7 

Turnip (roots) 12 

That is, if turnips were thoroughly dried at the 
temperature of 212, and 100 lbs. of this dried turnip 
burned, 12 lbs., of ash would be left. The following 
table gives the number of pounds of ash in a ton of 
various vegetable substances in their natural con- 
dition : 

Name of Substance. Ash in One Ton. 

Oats (grain) 70 lbs. 

Wheat (grain) 34 lbs. 

Indian corn (grain) 32 lbs, 

Wheat bran 122 lbs. 

Clover Hay 106 lbs. 

Meadow hay 124 lbs. 

Wheat straw 92 lbs. 

Meadow grass 40 lbs. 

Green clover 30 lbs. 

Potatos 20 lbs. 

Turnip 14 lbs. 

The ash of plants consists principally of lime, pot- 
ash, phosphoric acid, sulphuric acid, soda, magnesia 
and iron. Chlorine is occasionally present, and silica 
quite frequently (158). Minute portions of other sub- 
stances are frequently found, but do not seem essen- 
tial to the plant. 

181. Other Substances. — The remainder of the plant 
is composed of cellulose (119) and other carbohy- 
drates (117), lignose (119), albuminoids (126), pectose 



94 SCIENCE IN FARMING. 

substances (123), amides (128), vegetable acids (124), 
fats (125) and alkaloids (129). 

§ 2. Germination. 

182. A Seed is composed of two parts — the embryo 
and the endosperm. The embryo, commonly called 
the "chit," is the undeveloped plant. The en- 
dosperm forms the bulk of the seed, and is the pro- 
vision made by Nature for the nourishment of the 
young plant. 

183. Chemistry of Germination. — When a seed is sub- 
jected to favorable conditions of moisture, air and tem- 
perature, water and oxygen are absorbed, and certain 
chemical changes occur. The starch in the endosperm 
is converted into glucose and other soluble substances; 
fats, by combination with the elements of water, are 
changed into soluble carbohydrates; and albuminoids 
also become soluble. The nutriment in the seed is 
thus prepared for the use of the plant. 

Two stems are now thrown out from the embryo ; 
one, called the radical, turns downward into the soil, 
the other, called the plumule, turns upward and seeks 
the light. The substances in the endosperm that 
have been rendered soluble, are dissolved by the wa- 
ter absorbed, and carried through the growing plant, 
and in the proper places changed into cellulose and 
other insoluble substances. 

This process continues, the young plant being sup- 
ported by the nutriment stored in the seed, until that 
is exhausted, as it has no power to obtain any other 
food until the leaves are formed and exposed to the 
light. If the nutriment in the parent seed is exhaust- 
ed before the leaves reach the light, the young plant 
dies of starvation. 



PLANT GROWTH. 95 

184. Necessities of Germination. — These are oxygen, 
water and a proper temperature. The soil performs 
no part in the work except to furnish the proper con- 
ditions. Oxygen and water are both needed to effect 
the chemical changes by which the substances in the 
seed are rendered soluble, and water is necessary to 
dissolve them and convey them to the different parts 
of the growing plant. 

Numerous experiments have been made to deter- 
mine the lowest and highest temperatures at which 
germination is possible, and that at which it proceeds 
most rapidly. The following table gives the results 
with certain seeds : 

Lowest Highest Most Rapid 

Temperature. Temperature. Germination. 

Wheat and Barley 41 deg. 104 deg. 84 deg. 

Peas 44.5 '* 102 " 84 " 

Indian corn 48 '* 115 " 93 *' 

Squash 54 *' 115 '' 93 " 

Some other seeds will germinate at much lower 
temperatures. It is said that rye will germinate at 
any temperature above the freezing point. 

§ 3. Mow the Plant Grows, 

185. Plant Food. — The plant has no power to create 
any substance. It can therefore only grow by col- 
lecting certain elements from the soil and air and 
forming out of these the various organic compounds. 
The elements used by the plant are carbon, hydrogen, 
oxygen, nitrogen, phosphorus, sulphur, calcium, pot- 
assium, magnesium and iron. Without these ten, no 
agricultural plant can be formed, and deficiency in 
one cannot be made up by an over- supply of another. 
After germination, the plant obtains its food by means 
of its roots and leaves. 



06 Science m farming. 

186. The Roots gather from the soil all those sub- 
stances which form the ash of the plant, and also ni- 
trogen, usually in the form of a nitrate. These sub- 
stances are taken up in solution. The roots have 
power, however, to attack some substances that are 
not ordinarily soluble. This is due to the acid sap 
which they contain, and which dissolves some sub- 
stances when they are in direct contact with the roots. 
It is in this manner that plants obtain phosphoric acid 
— a substance that rarely exists in the soil in a solu- 
ble condition. The roots also obtain from the soil the 
water necessary for the growth of the plant. Solu- 
ble substances in the soil not essential to the plant, 
are often taken up by the roots. These are usually 
deposited in the older tissues, or as a crust upon the 
stem of the plant, and often serve a useful purpose 
by hardening the tissues and protecting them from 
injury. Carbonic dioxide is also taken up by the 
roots, but the amount is so small that the fact is of 
scientific interest, only. 

187. The Leaves absorb carbonic dioxide from the 
air. This is taken up by the minute pores of the 
leaves. These pores are called stomata, and are very 
numerous. An ordinary apple leaf has about 100,000 
to the square inch. The carbonic dioxide is decom- 
posed in the leaf, the oxygen being given off and the 
carbon uniting with the elements of water to form 
carbohydrates. The decomposition of the carbonic 
dioxide in the leaf is performed in what are called the 
chlorophyl cells. These cells contain a green liquid 
called chlorophyl, and to which the green color of the 
plant is due.* All green portions of the plant have 

*Plaiits which have no green color cannot obtain carbon 
from the air. These are chiefly parasites — which obtain their 



PLANT GROWTH. 97 

the power of decomposing carbonic dioxide, but the 
work is principally performed by the leaves. 

The plant obtains the power by which this decom- 
position of carbonic dioxide is accomplished, from the 
sunlight. The process ceases entirely in the darkness. 

All green plants are thus during the day-time con- 
stantly taking carbonic dioxide from the air and re- 
turning oxygen. 

Albuminoids and amides are formed from the solu- 
ble carbohydrates in connection with nitrogen and 
sulphur obtained from nitrates and sulphates in the 
sap. Fats are produced by the removal of a part of 
the oxygen and hydrogen of carbohydrates, and vege- 
table acids by their oxidation. 

The leaves absorb from the air a very small amount 
of ammonia, which is used by the plant in the forma- 
tion of albuminoids and amides. 

188. The soluble carbohydrates and other sub- 
stances when formed are carried in the sap to every 
portion of the plant, and its tissues are built up by 
the conversion of these soluble substances into cellu- 
lose, lignose, and other insoluble forms. Thus every 
part of the plant, including tEe roots, is built from the 
carbon obtained by the leaves. 

189. The plant has the power of rendering soluble 
substances that have been deposited in one part, con- 
veying them to another, and changing them into new 
forms. If a tree is stript of its leaves, it can no longer 
obtain carbon from the air, but carbohydrates already 
deposited in other parts of the tree will be taken up 
by the sap and used for the production of new leaves. 
If these are removed as rapidly as they are produced, 

carbon from the juices of the plants they live upon — or fungi, 
which obtain it from decaying organic matter. 
7 



98 SCIENCE IN FARMING. 

the tree will continue putting forth leaves until the 
available supply of material is exhausted, when it 
dies. 

During the fall the carbohydrates, albuminoids, 
phosphoric acid and potash contained in the leaves 
are largely re-absorbed and deposited in the trunk. 
With the coming of warm weather the sap begins to 
circulate, these substances are converted into soluble 
forms and used for the production of new leaves. The 
sugar in maple sap is produced from the starch stored 
up the previous fall. 

190. Respiration. — The plant is continually absorb- 
ing oxygen through the bark and leaves. This com- 
bines with carbon in the plant forming carbonic diox- 
ide, which is thrown oft'. This process continues both 
in daylight and darkness, and so closely resembles 
the respiration of animals that it has been given that 
name. 

During the daytime the amount of carbonic dioxide 
absorbed is many times greater than that given oft', 
and consequently the process of respiration is not 
noticeable, but in darkness when the absorption of 
carbonic dioxide ceases, the effect of respiration be- 
comes perceptible. Hence it is sometimes said that 
plants absorb carbonic dioxide during the day, and 
give it off during the night. The statement is not 
scientifically correct as respiration continues at all 
times, but its effects are hidden, in daylight, by the 
larger amount of carbonic dioxide absorbed^ and of 
oxygen given off.* 

*Fr6m the fact that plants give oflf carbonic dioxide in the 
night, the theory has been advanced that they are injurious rn 
bed-rooms. The amount of this gas given off is so minute that 
it could have no appreciable effect on the air of any ordinary 



PLANT GROWTH. 99 

§ 4. Formation of Seed. 

191. The Seed. — As we have seen (182), the seed 
contains nutritive matter in the most concentrated 
form, it being Nature's provision for the nourishment 
of the young plant until the time when it shall be 
able to collect food for itself. We therefore find in the 
seed every element needed for the life and growth of 
the plant. The composition of seed is more uniform 
than that of any other portion of the plant, and they 
never contain any of the unessential ash constituents 
sometimes taken up by the roots. 

192. Annuals. — These are plants which germinate, 
attain maturity, and produce their seed within a 
single season of growth. During the early part of the 
life of an annual, its energies are entirely devoted to 
the formation and development of the organs of nutri- 
tion, the leaves and roots. When the flower is put 
forth this process is checked, and as the formation of 
the seed progresses, less and less food is gathered 
from the soil and air, and the energies of the plant 
are devoted to gathering up the nutritive matter 
already formed within its tissues, changing them into 
more concentrated forms and depositing them in the 
seed. The final work of storing food in the seed is 
done after the plant has entirely ceased to collect 
food from without. 

Thus as seed formation in an annual progresses, 
the whole plant undergoes exhaustion, and, if the 
season is favorable,|,this exhaustion is very great. 
Consequently the straw of a crop is more valuable in 
a season unfavorable for the maturing of the grain. 

.room. A gi'owing plant absorbs during daylight a great deal 
jnore carbonic dioxide than itfgives off in 24 hours. 



100 SCIENCE IN FARMING. 

The extent to which this exhaustion of the plant is 
carried is shown in the following tables giving the 
percentage of soluble carbohydrates,* albuminoids, 
and crude fibref in the dry substance of various plants, 
before and after the formation of seed : 

RED CLOVER. 

Cut in Bloom. Cut When Ripe. 

Soluble carbohydrates 36.0 24.4 

Albuminoids .". 16.0 11.3 

Crude fibre 43.0 57.6 

RYE FODDER. 

Cut in Bloom. Ripe Straw. 

Soluble carbohydrates 55.0 31.5 

Albuminoids 12.2 1.8 

Crude fibre 26.9 63.0 

INDIAN CORN FODDER. 

Cut in August. Cut after Grain 
has ripened. 

Soluble carbohydrates 61.2 45.3 

Albuminoids 6.2 3.5 

Crude fibre 26.4 46.5 

The decrease in proportion of the nutritive sub- 
stances — especially albuminoids, is very noticeable in 
each case. 

It must be remembered that these tables give the 
percentage composition of the dry substance only, the 
purpose being to illustrate the exhaustion of the plant 
in the formation of seed. They cannot be used to 
compare the value of a ton of green rye fodder with a 
ton of rye straw, on account of the different amount 
of water. This part of the subject will be considered 
elswhere. 

193. Biennials. — These are plants which grow 

*The term '* soluble carbohydrates'-' is frequently used in 
analyses of foods to represent not only the true carbohydrates, 
but also the pectose substances (228). 

tCrude fibre consists of cellulose and lignose in such forms 
that they cannot readily be dissolved. 



PLANT GROWTH. 101 

through one season, producing only leaves and roots, 
and the next season throw up a flower stalk and pro- 
duce seed. Beets and cabbages are biennials. In 
these plants the first year's growth is devoted to col- 
lecting nutritive matters from the soil and air and 
storing them, either in a fleshy root, as in the beet, 
parsnip and carrot, or in a leafy head, as in the cab- 
bage. In the second season the flower stalk is thrown 
up and seed produced from the material that had 
been stored up during the first season.* 

194. The tuber of the potato and the bulb of the 
onion are similar storehouses of food. Men and ani- 
mals take advantage of these characteristics of vege- 
table life, and find much of the best and most concen- 
trated food in the seeds of annuals, and the roots of 
biennials — gathered at the close of the first season — 
or if they use the whole plant do so before the pro- 
duction of seed begins. 

§ 5. Summary and Practical Application. 

195. Germination. — The necessities of germination 
are water, air, and a suitable temperature. When the 
pores of the soil are filled with water, germination is 
greatly retarded, as the water excludes the air. Too 
deep planting retards germination for the same rea- 
son. As moisture is essential, it is necessary that the 
soil should be well pulverized, otherwise the seed 
may fall into cavities between the lumps of soil and 
be unable to obtain sufficient moisture ; or if damp- 
ness of the weather at the time of sowing the seed en- 
ables it to germinate, a few dry days following may 

*A plant cannot take up by its roots and use organic matter 
in the soil, but it can take organic matter from one part of its 
own structure and use it for building up some other portion. 



102 SCIENCE IN FARMING. 

cause the young plant to perish before its roots can 
penetrate the soil far enough to obtain a supply of 
moisture. As warmth is necessary, seed sown before 
the ground has become sufficiently warm is liable to 
rot instead of germinating. Indian corn, especially, 
requires a considerable degree of warmth, and a •■' bad 
stand " is often the result of planting in cold ground. 

As the parent seed is the only source from which 
the young plant can draw nourishment until its leaves 
reach the light, when seeds are too deeply planted, 
the young plant may exhaust this nutriment and die 
from starvation before its leaves reach the light. 
Hence, also, if the leaves are torn from a young plant 
just as germination is completed, it dies, being de- 
l^rived of means of obtaining food from soil and air, 
and having no source of supply within itself. If the 
plant is allowed to grow for a time after germination, 
a supply of material is laid up within its own tissues 
which can be used for the production of new leaves. 
A practical knowledge among farmers of the working 
of this principle has given rise to the expression that 
" the best time to kill weeds is before they come up," 
by which is meant just as the process of germination 
is completed. 

196. Plant Food. — As the plant cannot use the ni- 
trogen contained in organic matter in the soil until it 
has been oxydized into nitric acid, it is necessary to 
expose the soil thoroughly to the action of the air, in 
order to secure a sufficiency of available plant food. 
The nitrogen in urea being available for the use of 
the plant without first being oxydized, urine acts very 
rapidly as a fertilizer. As, when one element of plant 
food is deficient, the i)lant is incapable of using other 
food, however abundant it may be, it is necessary to 



PLANT GROWTH. 103 

see that all the elements of plant food needed are con- 
tained in the soil and in an available condition. As 
the carbon in the plant is obtained wholly from the 
air, carbonaceous matters in manures are without 
value as plant food. 

197. The Growing Plant. — As the whole plant, in- 
cluding the roots, is built up from carbon obtained by 
the leaves, no growth can be made after the leaves 
have been removed, and hence, if insects are allowed 
to continually destroy the leaves of trees, the trees 
themselves will ultimately die. Hence, also, if weeds 
are constantly cut down and not permitted to put 
forth leaves, the roots will ultimately perish. In 
order to kill a weed in this way, however, the leaves 
must be removed as rapidly as produced, for if they 
are allowed to remain even for a short time, they will 
lay up another store of surplus material. 



CHAPTER VIII. 



SCIENCE IN ANIMAL LIFE 



§ 1. Composition of the Animal. 

198. General Composition. — Animal substances are 
composed of the same ten elements as vegetables (185) 
with cholerine and sodium in addition. These two 
last elements form in combination common table salt 
(106), and though not essential to plant life, are usu- 
ally present in vegetable substances. 

199. Organic Compounds. — These are principally 
Albumnoids Gelatinoids, Keratin (127) and fats. Car- 
bohydrates do not exist in the animal body except in 
the form of partially consumed food. 

200. Ash. — The ash consituents are principally 
found in the bones, of which about 55 per cent, is 
tricalcic phosphate. Iron and potash are also found 
in all parts of the system. 

201. Water. — As in the plant, the larger part of the 

living animal is water. The following table shows the 

average composition of a half fat ox, weighing 1,000 

lbs. exclusive of stomach and intestines: 

Water 560 

Nitrogenous matter 181 

Fat 208 

ABh : 51 

1,000 



ANIMAL LIFE. 105 

202. Comparison with Vegetable Matter. — The ani- 
mal contains less carbon, hydrogen, and oxygen than 
the plant and more nitrogen, phosphoric acid and lime. 
The following table shows the number of pounds of 
these contained in 1,000 lbs. of a fat ox, (exclusive 
of stomach and intestines) and in an equal weight of 
fresh clover in bloom: 

Fat Ox. Fresh Clover. 

Nitrogen 23.18 5.10 

Phosphoric acid 16.52 1.40 

Lime 19.20 4.80 

§ 2. Animal Nutrition, 

203. We have seen that the food of plants consists 
of gasses, mineral salts, and water, out of which it 
forms all of its various organic compounds. The 
power by which these transformations are accom- 
plished is obtained from a source outside of the plant 
— the light of the sun. 

The animal is unable to construct organic matter 
out of inorganic, nor can it obtain power for carrying 
on the functions of life, from any outward source. It 
must therefore find in its food, in forms that will re- 
quire but little change, the materials it needs, for 
growth; and, also the source of animal heat and en- 
ergy. The plant is therefore the machine by which 
inorganic matter is prepared for the use of the animal 
and the medium through which the energy derived 
from the light and heat of the sun is made available 
for the purposes of animal life. 

204. Digestion. — The food of animals consists of 
carbohydrates, albuminoids, fat and mineral salts con- 
tained in the plant. These are fitted for animal nu- 
trition by the process of digestion. Some of the car- 
bohydrates, such as sugar require but little change. 



106 SClENCt: m FARMING. 

Others, such as starch and cellulose must be converted 
into glucose. This change is begun by the action 
of the saliva, and is completed in the intestines. The 
albuminoids are rendered soluble by the action of the 
gastric juice secreted by the stomach, and also by the 
pancreatic juice. The digestion of fats is accomplished 
by the bile and pancreatic juice. 

205. Assimilation. — After the food has been ren- 
dered soluble, or digested, it is absorbed by the mi- 
nute blood vessels lining the intestines and by vessels 
called the lacteals, and carried by the blood to every 
part of the body. Each part takes from the blood 
the needed material for its own growth or repair, and 
changes it into substance like itself. This is called 
assimilation. Thus all parts of the body are nour- 
ished by the blood. How the tissues make the selec- 
tion from the blood, of the particular materials they 
need, is not understood. 

206. Waste of the Body.— The tissues of the body 
are continually undergoing oxidation and decay. The 
waste matter thus produced is taken up by the blood, 
and removed from the system through the excretory 
organs. This waste is repaired by the blood which 
serves both to bring the new material and remove that 
which is worn out. 

207. Respiration. — By the action of the heart, the 
blood is forced through the lungs. Owing to the pe- 
culiar structure of these organs, it is here very thor- 
oughly exposed to the air, and absorbs oxygen, 
which gives it a bright scarlet color. In the circula- 
tion of the blood the oxygen thus absorbed, combines 
with the carbon of the food, the process being similar 
to combustion (131). The carbonic dioxide formed 
by this process is given off by the lungs. When car- 



ANIMAL LIFE. 107 

bohydrates suffer oxidation in the blood the i)roducts 
are carbonic dioxide and water. When albuminoids 
or amides are oxidized the nitrogen is separated in the 
form of urea (OON2H4) a substance containing 46.67 
per cent of nitrogen, and which is removed from the 
blood by the kidneys. 

208. Excretion is the process by which waste or 
useless material is removed from the body. The prin- 
cipal organs of excretion are the lungs, kidneys and 
skin. Carbonic dioxide, water and small portions of 
waste organic matter are thrown of by the lungs, and 
skin. The kidney removes the urea produced by the 
oxidation of nitrogenous substances, and the mineral 
salts. The solid excrement is composed of the undi- 
gested portions of the food, with a small amount of 
bile, and secretions of the intestines. 

§ 3. Uses of Food in the Body. 

209. The principal uses of food are : 

1. To furnish material which can be burned in the 
body for the production of heat and energy. 

2. To supply material for growth. 

3. To repair the waste of the body (206). 

4. To produce fat, 

5. The production of milk. 

210. In the construction of fat, flesh, or milk, the 
animal must find in the food all the elements which 
the substances to be formed will contain. From a 
carbohydrate it can produce fat, because they contain 
the same elements, the difference being only in the 
proportions in which they are combined. It can also 
produce fat from an albuminoid, by the removal of the 
nitrogen, but it cannot produce an albuminoid from 



108 SCIENCE IN FARMING. 

fat or a carbohydrate, as neither of these substances 
contains nitrogen, which is an essential element in 
the albuminoid. 

Albuminoids are therefore capable of meeting all 
the requirements of the body, and can support life 
without any other food. Fats and carbohydrates can 
be used for the production of fat, and to furnish car- 
bon for combustion in the blood. 

The respective values of these different classes of 
foods will be considered in the next chaj)ter. 

211. Source of Animal Heat and Energy. — We have 
seen (37) that in the locomotive, energy that had been 
obtained from the sun by plants long ages ago, is set 
free, by the combustion in the fire-box, of the carbon 
of the coal, and that this energy is applied to useful 
work by the machinery of the engine. In the animal 
the energy derived from the sun by agricultural plants 
is set free by the combustion, in the blood, of the car- 
bon of the food, and the muscles and organs of the 
body are the machinery by which this energy is ap- 
plied to useful work. Part of it is expended in main- 
taining the heat of the body, part in carrying on the 
processes of respiration, digestion, circulation, etc., 
and part may be used by the animal in physical exer- 
cise or useful work. The combustion of a given 
amount of carbon from the food, will produce a given 
amount of energy and no more. If more of this en- 
ergy is used for maintaining the heat of the body, less 
can be used in the performance of work, and if an in- 
creased amount of heat and work is needed, there 
must be an increased consumption of food. 

§ 4. Disposition Made of the Food. 

212. Heat and Energy. — By far the greater portion 



ANIMAL LIFE. 109 

of the food consumed by the animal is used in the 
production of heat and energy. The heat of the body 
must be maintained, and even when the animal is at 
rest a large amount of energy is used in the processes 
of digestion, respiration, circulation, etc. In a fatten- 
ing animal, the amount of food used in this manner 
is from three to ten times as great as the amount used 
in the production of increase. In animals that are 
not growing or laying on fat, the proportion of food 
used for the production of heat and energy is still 
greater. If the food contains a due proportion of car- 
bohydrates and fat, these will be used for this purpose 
rather than the albuminoids. 

213. Growth and Repair. — The albuminoids in the 
food are used for producing new tissues, and also for 
repairing the necessary waste. The amount required 
for this latter purpose is but small. An ox weighing 
1,000 lbs. will require only five- or six-tenths of a 
pound of albuminoids per day to repair the waste of 
tissue. Albuminoids consumed in excess of the 
amount required for growth and waste, are either 
burned for production of heat and energy, or convert- 
ed into fat. In either case the nitrogen is separated 
in the form of urea. 

214. Production of Fat. — When more food is con- 
sumed and digested by the animal than is required 
for growth, the repair of waste, and production of heat 
and energy, the surplus will be converted into fat, 
and stored up to meet future demands of the system. 
The production of fat is in fact the one method by 
which the animal can dispose of food consumed in ex- 
cess of immediate needs. 

215. Milk. — When an animal is giving milk, a 
large amount of the foo4 consumed is used in its pro- 



110 SCIENCE IN FARMING. 

duction. Fats and carbohydrates are used in form- 
ing the fat and sugar, and albuminoids for the casein. 
A large amount of mineral salts are also used in milk 
production. 

216. The mineral salts obtained in the food are 
largely used in the production of the bones. Those 
not used are removed by the kindeys. 

217. Undigested Food. — The animal never digests 
all the food it consumes. The amount left undigested 
varies with the kind of food and the animal. It is 
seldom less than five, and sometimes as much as sixty 
per cent of the dry matter of the food consumed. 
This undigested food passes oiff in the solid excrement. 

§ 5. Effects of Insufficient Food. 

218. Insufficient Albuminoids. — When the albumin- 
oids supplied to an animal in its food are but just 
sufficient to repair the waste of tissue, muscular growth 
will necessarily cease. If the amount of albuminoids 
in the food is insufiicient to repair the waste, the ani- 
mal will gradually shrink in weight, and finally die of 
starvation, even though abundantly supplied with non- 
nitrogenous food constituents. Instances are on re- 
cord of children who have died from starvation while 
being fed on a purely farrinaceous (starchy) diet. In- 
jury to children raised by hand, from insufficient al- 
buminoids in their diet is more common than is usti- 
ally^known. 

219. Insufficient Non-Nitrogenous Constituents. — 
When carbohydrates and fat in the food are insuffici- 
ent to meet the demands for the production of heat and 
energy, the albuminoids will be burned for this pur- 
pose, even though growth is stopped and the wastes of 
the body go unrepaired. In this manner, deficiency 



ANIMAL LIFE. Ill 

of non-nitrogenous matter in the food may cause loss 
of muscular weight, although these substances are not 
capable of conversion into muscle. Owing to the 
same principle, an increase of non-nitrogenous matter 
in food may cause an increase of muscular develop- 
ment, provided the food already contains a due pro- 
portion of albuminoids. The increase in such a case 
is not due to the conversion of the non-nitrogenous 
substance into muscle, but to the fact that they sup- 
ply carbon for the production of heat and energy, and 
thus prevent the albuminoids from being used for this 
purpose. 

220. Starvation. — When the food is insufficient to 
meet the needs of the animal, not only is waste left 
unrepaired, but fat that had previously been de- 
posited is re-absorbed into the blood and burned in 
place of food. If the deficiency of food continues, 
the muscular substances will also be attacked and 
absorbed. This process will continue until the ani- 
mal can no longer obtain from its own tissues 
material to produce, by its combustion, sufficient heat 
and energy to maintain the vital processes, and the 
animal dies. 

§ 6. Effects qf Exercise and Exposure to Gold. 

221. As we have already seen, the first use of food 
is for the production of heat and energy. When an 
animal is exposed to cold, the amount of heat re- 
quired to maintain the temperature of the body|will 
be increased, and a larger proportion of the food con- 
sumed by the animal must be used in its produc- 
tion. 

222. Physical work can only ^be performed by 
means of the energy derived|from the^ combustion of 



112 SCIENCE IN FARMING. 

food in the system. Consequently every increase of 
physical exercise increases the amount of food that 
must be used in the production of energy. 

223. The first effect, therefore, of exposure to cold, 
or of exercise, is an increased appetite, by which Ma- 
ture indicates that more food is needed. If the in- 
creased food is not provided, the effect on the animal 
will be re-absorption of fat, and, in extreme cases, 
waste of muscular substance. 



CHAPTER IX. 



SCIENCE IN POODS. 



§ 1. Food Constituents, 

224. Food is composed of yarious organic sub- 
stances combined in varying proportions. Vegetable 
substances will vary in composition according to the 
soil and season, and the treatment they have received. 
All statements of the composition of food are there- 
fore approximate only. The nutritive constituents of 
foods are usually classed as : 

Albuminoids. 

Amides. 

Fats, 

Soluble carbohydrates. 

Crude fibre. 

Ash. 

225. The term albuminoids is used to include all 

nitrogenous matters in food that can be used for the 

formation of albuminoids in the animal system. In 

a great many analyses all the nitrogenous substances 

in the food are classed as albuminoids. In many 

substances this is unavoidable, as the proportion of 

the nitrogen contained in the amides has not yet been 

determined in all cases. 
8 



114 SCIENCE IN FARMING. 

226. Amides cannot be used by the animal for the 
production of albuminoids, but can be burned in the 
system as a source of heat and energy. They exist 
principally in roots and immature substances. 

227. The term " soluble carbohydrates " in analy- 
ses of foods includes all non-nitrogenous substances 
(excepting ash and fats) that can readily be dissolved 
by weak acids or the juices of the stomach. 

228. Crude fibre includes the coarser and harder 
portions of cellulose and lignose that are not readily 
dissolved by weak acids or the juices of the stomach 

229. In many analyses of foods the division is 
made into flesh formers, heat producers and ash. Un- 
der the term " flesh formers " are included all nitro- 
genous substances, and under " heat producers " all 
that do not contain nitrogen. The terms, however, 
are incorrect and misleading. 

§ 2. Composition of Foods. 

230. The figures in the following table give the 
average results of a number of analyses. They repre- 
sent about the composition of any ordinary lot of 
food, but cannot be relied on as positively accurate, 
as the composition of diff'erent samples of the same 
kind of food is rarely the same. The variation in com- 
position is but small in seeds and grains, but in roots, 
straw and fodder is often quite considerable. The 
column of " Total nitrogenous matter" may, in most 
cases, be considered reasonably near the truth, but 
some doubt exists as to the figures in the column of 
" True albuminoids," owing to the uncertainty with 
regard to some foods, particularly roots and fodder, as 
to the proportion of the nitrogen that exists in the 



FOODS. 



115 



form of amides and nitrates.* In many cases it has 

POUNDS OF EACH CONSTITUENT IN ONE TON OP VARIOUS FOODS. 



Name of Foood. 









I 73 






O t-t S~t 



O 



GRAINS, CAKES, ETC. 

Cotton cake, decorticated 

Cotton cake, undecorticated . . . 

Linseed cake 

Beans 

Peas , 

Oats 

Wheat 

Barley 

Rye 

Indian corn 

Wheat bran 

Corn cobs 

HAY AND STRAW. 

Meadow hay 

Clover hay 

Lucerne hay, cut in bloom . . . . 

Wheat straw 

Oat straw 

Corn fodder 



GREEN FODDER. 

Meadow grass 

Clover 

Rye 

Lucerne, in blossom 

Peas 

Hungarian grass in blossom . . 

Sorgum 

Indian corn 



200 


.824 


740 


280 


360 


230 


492 


443 


124 


604 


240 


562 


506 


240 


606 


290 


510 


459 


32 


918 


286 


448 


404 


40 


1050 


260 


258 


232 


120 


1076 


288 


226 


203 


30 


1362 


280 


212 


191 


40 


1274 


286 


220 


198 


40 


1384 


228 


208 


187 


102 


1370 


280 


284 


200 


84 


1008 


206 


28 


9 


28 


880 


286 


194 


155 


50 


820 


320 


246 


196 


44 


764 


334 


288 


230 


50 


450 


286 


60 


? 


30 


652 


286 


50 


? 


40 


764 


280 


60 


? 


22 


780 


1600 


70 


? 


16 


384 


1660 


66 


? 


14 


140 


1458 


66 


? 


18 


298 


1480 


90 


? 


14 


140 


1630 


64 


? 


12 


164 


1312 


118 


? 


30 


300 


1480 


50 


? 


28 


306 


1644 


22 


? 


10 


218 


1500 


42 


25 


6 


410 


1770 


24 


6 


2 


164 


1834 


22 


10 


4 


106 


1890 


26 


? 


2 


56 


1630 


20 


? 


2 


308 


1700 


30 


? 


4 


216 



180 

416 

220 

188 

128 

216 

60 

142 

70 

60 

222 

756 

526 
520 

800 
880 
800 
800 

90 
90 
146 
250 
112 
230 
146 
94 

ROOTS, ETC 

Potatos 1500 42 25 6 410 22 

Mangel wurzel 1770 24 6 2 164 20 

Turnips 1834 22 10 4 106 20 

Pumpkins 1890 26 ? 2 56 20 

Sugar beets, small 1630 20 ? 2 308 26 

Carrots 1700| 30 ? 4 216 34 

not been possible to give the amount of true albumi- 
noids. 



*It was formerly supposed that all the nitrogen contained in 



116 SCIENCE IN FARMING. 

231. The composition of straw depends very much 
on the season. In seasons that have been unfavora- 
ble for maturing the grain, the straw contains consid- 
erably more soluble carbohydrates and albuminoids 
than indicated in the table (192). Only a small por- 
tion — probably less than half — of the nitrogen in straw 
exists in true albuminoids. 

232. The composition of hay depends greatly on 
the date of cutting. The following table gives the 
number of pounds of nutritive substances in a ton of 
hay made from grass cut at three different periods. 
The first date represents grass younger than it would 
usually be cut for hay, but such as cattle get on a 
good spring pasture. The second date represents 
good early cut, well cured hay. The third date rep- 
resents a quality of hay cut rather late, and rather 

coarse and stemmy : 

May 14. June 9. June 26. 

Nitrogenous matter 303 191 145 

Fat 55 47 46 

Soluble carbohydrates 700 742 743 

Crude fibre 394 598 654 

It will be seen from this table that grass in early 
spring contains a larger proportion of nitrogenous 
matter and fat than it does later in the season. In 
the more mature crop, however, a larger proportion of 
the nitrogen is contained in true albuminoids. 

233. Root crops, as they approach maturity, con- 
tain more valuable nutritive constituents than when 



foods was available for the use of the animal, and the albumi- 
noids were reckoned by first ascertaining the amount of ni- 
trogen contained in the food and multiplying this by 6.25. 
Many errors have arisen from this method, as in some foods 
as much as 75 per cent of the nitrogen exists in amides and ni- 
trates. Foods have thus been supposed to have a high albu- 
minoid ratio (255), when in fact they were very deficient in al- 
buminoids. 



FOODS. 117 

immature, a portion of the fibre being converted into 
starch and sugar. 

234. Water in Foods. — It will be noticed that pota- 
tos, the dryest of the roots, contain three-fourths of 
their weight of water, while turnips are nine-tenths 
water. This is a matter that is of considerable im- 
portance in determining the proper mixture of foods, 
and will be more fully considered in the next chapter. 

235. Variations Caused by Soil and Season. — Foods 
grown in wet seasons and on heavily manured soil, 
usually contain more than the average per cent of 
water (178). Root crops grown on rather poor soil 
contain a larger per cent of nutritive matter than 
those grown on soil that has been heavily manured. 
The dry substance in a crop grown on soil that has 
been heavily manured, usually contains a larger per 
cent of ash and of nitrogen than the dry substance of 
a crop grown without manure. A larger portion of 
the nitrogen in the manured crop will be in the form 
of amides and nitrates. 

236. Effect of Methods of Preparing Foods.— Hay 
that has been roughly handled contains a smaller pro- 
portion of valuable constituents than that which has 
been more carefully treated, as the finer portions of 
the blades and leaves, which contain more albumi- 
noids and less crude fibre than the stems, are crum- 
bled and broken off. Clover, especially, is liable to 
deterioration in this way, as the leaves, which are 
rich in albuminoids, crumble readily when too dry. 
The chemical composition of a ton of clover which 
had been roughly treated, would be quite diff'erent 
from that of a ton which had been properly cured. 
If grass, after cutting, is exposed to drenching rains, 
part of the soluble constituents]] will be washed out. 



118 SCIENCE IN FARMING. 

and its composition will therefore show a larger per- 
centage of crude fibre. Hay that has undergone fer- 
mentation in the field will have suff*ered a further loss 
of soluble carbohydrates by their conversion into car- 
bonic dioxide and water. 

When properly handled and cured, the composition 
of hay does not differ materially from that of the grass 
from which it was made. 

§ 3. Digestibility of Foods. 

237. The composition of a food cannot be taken, 
alone, as a trustworthy indication of its feeding value, 
as this will depend largely on its digestibility. Some 
foods are almost entirely digested, while of others 
more than half is sometimes rejected (217). 

238. An animal does not always digest the same 
proportion of each constituent in a food, nor the same 
proportion of the same constituent in different foods. 
Thus, a cow will digest a much larger proportion of 
the albuminoids in lucerne hay than of those in clover 
hay, and will digest a larger proportion of the fat in 
clover hay than of that in lucerne hay. The digesti- 
bility of foods thus influences not only their compara- 
tive feeding value, but also their relative character. 
Thus the difference as an albuminoid food in favor of 
lucerne hay over clover is greater than indicated in 
the table on page 115. LiJiewise the table shows lu- 
cerne hay as containing a larger proportion of fat than 
clover ; yet so much more of the fat contained in clo- 
ver is digested, that as a food it is really richer in fat 
than lucerne. It will thus be seen that while such a 
table as given on page 115 is very useful for many 
purposes, yet, taken alone, it cannot be depended on 



, FOODS. 119 

to determine either the value of a food, or its char- 
acter.* 

239. The following table gives the number of 
pounds of digestible constituents in a ton of several 
different foods as determined by experiments with 
cattle and sheep. It will be noticed that in many re- 
spects'jt differs materially from the last table : 

Name of Nitrogenous -rr^. Soluble Car- tp,->,„„ 

Food. Matter. ^^^' bohydrates. -^^'^^®' 

Linseed cake 472 21(3 ' 473 ? 

Beans ....449 30 854 ? 

Oats 204 101 818 52 

Barley 163 40 1108 ? 

Indian corn 164 87 1247 ? 

Wheat bran 213 42 706 82 

Meadow hay 109 23 508 300 

Clover hay 135 25 527 229 

Lucerne hay 219 19 301 320 

Oat straw 19 12 329 488 

Wheat straw 12 11 254 494 

240. In this table it was impossible to make any 
accurate calculation of the amount of true albumin- 
oids in the digested portion of the food. It will prob- 
ably be safe to assume, however, that true albumin- 
oids formed 90 per cent of the digested nitrogenous 
matter in the cakes and grains — 80 per cent in hay 
and 50 per cent in straw. Roots appear to be almost 
completely digested. 

241. The horse digests a smaller proportion of 
coarse foods than ruminating animals, but on grains 
and concentrated food his digestion is equal or 
superior to theirs. 

242. Pigs have great powers of digesting concen- 
trated food, and can digest a good proportion of green 
foods when supplied in moderate amount, but they 

*By the ''character" of a food is meant its richness in any 
particular constituent, as albuminoids or fat. 



120 SCIENCE IN FARMING. 

do not successfully digest large quantities of coarse 
food. 

243. The degree of maturity of a crop has much 
to do with its digestibility. Young grass is more di- 
gestible than that which is older. The number of 
pounds of food constituents in a ton of hay cut at 
different dates was given in paragraph 232. We now 
give the number of pounds of digestible food constitu- 
ents in a ton of hay cut at the same three dates : 

May 14. June 9. June 26. 

Nitrogenous matter 222 138 80 

Fat 86 24 20 

Soluble carbohydrates 530 459 414 

Crude fibre 313 393 400 

By comparison with the proceeding table, the great 
depreciation in the value of the crop, as it approached 
maturity will be noticed. Not only does the older 
grass contain a smaller proportion of the more valu- 
able constituents, but a smaller proportion of what it 
does contain is digested. 

For this reason, young grass or clover pastured, or 
cut and fed green gives greater returns in beef or 
milk than the same amount of grass allowed to ma- 
ture and made into hay. This also explains why cat- 
tle do so well on spring i)astures. 

244. Digestibility of Food as Affected by Mixing. — 
To secure the most complete digestion of food, a cer- 
tain proportion between the nitrogenous and non-ni- 
trogenous constituents must be secured. 

245. If, to a diet of hay or straw, a food rich in al- 
buminoids is added, the digestibility of the Avhole ra- 
tion is not impaired, but if to such a diet a food de- 
ficient in albuminoids is added, the proportion of the 
hay or straw digested will be diminished. Potatos, 
and other foods rich in starch, have a greater effect 



FOODS. 121 

in reducing the digestibility of a diet with which they 
are mixed than mangels or other roots rich in sugar. 

246. If to a diet of hay or straw, potatos or some 
similar food is added, and also some food rich in albu- 
minoids, such as peas, beans, or linseed cake, the di- 
gestibility of the diet will not be reduced. 

247. The results of experiments in this direction 
show that in order to secure the most perfect diges- 
tion of food, the diet must contain a certain propor- 
tion of albuminoids. If a diet is mixed in such a 
manner that it does not contain a sufficient proportion 
of albuminoids, a larger percentage of all the nutri- 
tive constituents in the diet will remain undigested. 
It is therefore important in determining on a mixed 
diet to consider what its albuminoid ratio (255) will 
be, and to so proportion the food that this ratio ( cal- 
culated from the whole food) will not fall below that 
which secures the most perfect digestion of all the 
food constituents. The proper albuminoid ratio will 
be considered in the next chapter. 

§ 4. Valuation of Foods. 

248. For development of muscle no comparisons 
can be made between albuminoids and non-nitrogen- 
ous substances, as only the albuminoids in the food 
can be used for this purpose. If a diet is deficient in 
albuminoids, the addition of a sufficient quantity of 
them will have an efi'ect out of all proportion to the 
actual value of the albuminoids. 

249. As albuminoids, carbohydrates and fats can 
all be used for laying on fat, or can be consumed in 
the system for the production of heat and energy, it 
is easy to make a comparison of their respective 
values for these purposes. By careful experiments 



122 SCIENCE IN FARMING. 

these values have been determined, as follows : 

Fat 100 

Albuminoids 47.4 

Carbohydrates* 43.1 

These figures refer to the value of the digested por- 
tions of the food. A given weight of a very digesti- 
ble carbohydrate might be of more value than an equal 
weight of an indigestible fat, but the proportion be- 
tween the value of 1 lb. of digested fat and 1 lb. of di- 
gested carbohydrate is that of 100 to 43.1. That is if a 
given weight of fat in a food were worth $1.00, an equal 
weight of albuminoids would be worth 47y\ths cents, 
and an equal weight of carbohydrates, 43Yi^th cents. 

250. The rule usually adopted in comparing the 
value of fats with carbohydrates is to multiply the 
amount of fat by 2.44. That is, if one lot of food con- 
tained 100 lbs. fat and another 244 lbs. carbohydrates, 
they would be estimated of equal feeding value. 

251. To illustrate. By reference to the table in 
paragraph 239 it will be seen that a ton of linseed 
cake contains 216 lbs. digestible fat, and 473 lbs di- 
gestible carbohydrates. To estimate the feeding value 
of the digestible constituents in a ton of linseed cake, 
we multiply the fat by 2.44 and add to this the carbo- 
hydrates. Thus : 

Number of pounds 216 

Multiply by 2A4 

864 
864 
432 

Equal in carbohydrates to 5 2 7.0 4 

Add carbohydrates 473 

1000.04 



*This includes all digestible non-nitrogenous food constitu- 
ents except fats. 



FOODS. 123 

By which we see that the feeding value of the 
digestible non-nitrogenous constituents in a ton of 
linseed cake is equal to IjOOOyl-Q-ths lbs. of starch or 
other digestible carbohydrates. 

252. The rule for reducing fat to its equivalent 
value in starch, or other digestible carbohydrates, is : 
Multiply the number of pounds of fat by 244 and 
point off the last two figures in the product for deci- 
mals. 

253. As already stated, the value of a food, pro- 
viding it contains a sufficient amount of albuminoids 
to meet animal requirements, depends on its capacity 
for the production of heat and energy. By taking 
the digestible constituents of different foods and re- 
ducing them all to their value in carbohydrates, their 
respective values have been approximately deter- 
mined. 

254. The following table gives the result of these 
calculations, Indian corn being taken as the standard 
with which the others are compared. The first column 
g^^ the respective values of foods in their ordinary 
connition, the second column the respective values of 
the dry substance in these foods : 



Name of Food. 

Indian corn 

Linseed cake* . . , 

Beans 

Barley 

Oats 

Wheat bran 

Meadow hay . . . . 
Wheat straw . . . . 

Potatos 

Mangels 



Ordinary Con- 
dition. 
100 


Dry Sub- 
stance. 
100 


95 


96 


93 


96 


85 


88 


80 


81 


67 


69 


59 


61 


47 


49 


30 


105 


13 


100 



*It may appear strange that linseed cake is given a position 
as a food inferior to Indian corn. It must be remembered that 



124 SCIENCE IN FARMING. 

The figures for the last five articles are probably too 
high, owing to the fact that proper deduction has not 
been made for the amides and nitrates. 

§ 5. Albuminoid Ratio. 

255. The " albuminoid ratio" of a food is the pro- 
portion that exists between the albuminoids and the 
non-nitrogenous constituents. 

It is customary in calculating the albuminoid ratio 
of a food to take into consideration the digestible por- 
tion only, as the portion undigested of course has no 
feeding value. When the digestibility of the diff'erent 
constituents of a food is not known, the albuminoid 
ratio must be calculated from its total constituents. 
A food will usuallj^ appear richer in albuminoids 
when the estimate is made from the table of digesti- 
ble constituents than when calculated from the table 
of total constituents, as there is usually a larger per- 
centage of carbohydrates, fat and fibre rejected, undi- 
gested, than of albuminoids. 

256. To secure strict accuracy in the determina- 
tion of the albuminoid ratio, the calculation sl||p^d 
be made from the amount of true albuminoids only, 
as the amides and nitrates are without value in the 
production of muscle. Nearly all the older calcula- 
tions are erroneous from this cause, as it is only lately 
that the distinction between amides and true albu- 
minoids has been learned. It is still sometimes nec- 
essary to make calculations in this way, as, with 
some foods, the proportion of nitrogen which exists 
in true albuminoids has not been ascertained with 



this table is calculated only on the capacity of the food for pro- 
ducing heat and energy. Linseed cake mixed with other foods 
may, by increasing the albuminoid ratio of the mixed diet, 
have a value many times greater than that of corn. 



FOODS. 125 

certainty. Calculations made in this manner will be 
reasonably correct with respect to grains and concen- 
trated foods ; but with roots and immature substances 
such calculations are liable to be seriously incorrect. 
Thus, mangels were formerly supposed to contain suf- 
ficient albuminoids to form a complete ration, their 
albuminoid ratio being 1 : 8, when calculated on the 
supposition that all the nitrogenous matter they con- 
tained was in albuminoids ; but when only the true 
albuminoids were reckoned, the ratio was found to 
be 1 : 31.8 (263). 

257. To determine the albuminoid ratio of a food, 
the feeding value of the digestible non-nitrogenous 
constituents is ascertained, and this is divided by the 
amount of albuminoids. The product is the proportion 
of non-nitrogenous to one of nitrogenous constituents. 

258. Illustration. — Suppose the albuminoid ratio of 
wheat bran is desired. By reference to the table in 
paragraph 239, we find that a ton of wheat bran con- 
tains the following amounts of digestible constituents : 

Albuminoids* 213 lbs. 

Fat 42 lbs. 

Carbohydrates 706 lbs. 

Fibre 82 lbs. 

First reduce the fat to its equivalent in starch (250) : 

Fat 4 2 lbs. 

Multiply by 2Ai 

168 
168 

84 

The fat is equal in starch 1 2.4 8 lbs. 

Add digestible carbohydrates ..706 lbs. 

And digestible fibre 82 lbs. 

8 9 0.4 8 lbs . 

*In this instance it is necessary*to reckon all the nitrogenous^ 



126 SCIEKCE IN FARMING^. 

Which gives us the feeding value of the digestible 
non-nitrogenous constituents of a ton of bran as equal 
to 890.48 lbs. To get the proportion between this and 
the albuminoid, we divide it by the number of pounds 
of albuminoids. Thus : 

213)8 9 0.4 8(4.18 

852 

384 
213 



1718 
1704 



We thus get the proportion of one to four and eighteen 
one-hundreths, which is written thus : 1 : 4.18. 

259. When the proportion of albuminoids in a food 
is large, it is said to have a high albuminoid ratio. 
When the proportion is small, that food is said to 
have a low albuminoid ratio. Thus the albuminoid 
ratio of decorticated cotton cake is 1:1.5; that of 
wheat straw 1 : 64.4 ; cotton cake is said to have a 
high, and wheat straw a very low, albuminoid ratio. 

260. To Determine the Albuminoid Ratio of a Mixed 
Diet. — This is a matter of great importance, as it ena- 
bles the farmer to know whether a mixed diet is prop- 
erly proportioned to meet the desired object. 

261. Rule. — Ascertain the number of pounds of 
each digestible constituent in the amount of each food 
used in the mixture ; add these and calculate the al- 
buminoid ratio of the product, the same as in any 
other case. 

262. Illustration. — Suppose a farmer wishes to use 

matter in the bran as albuminoid, as the per cent of amides 
contained in the digested portion of bran has not been fully de- 
termined. 



FOODS. 127 

a mixed diet arranged in the following proportion : 

Meadow hay 100 lbs. 

Corn meal 20 lbs. 

Bran 20 lbs. 

By reference to the table in paragraph 239, we learn 

the amount of each digestible constituent in one ton 

of each food named, and by a simple calculation we 

obtain the number of pounds of digestible substance in: 

Nitrogenous y . Carbohy- -p.. 
Matter. ^^^- drates. ^^^^®' 

100 lbs. meadow hay... 5.45 1.15 25.40 15.00 

20 lbs. corn meal 1.64 .87 12.47 

20 lbs. bran 2.13 .42 7.06 .82 

Totalm whole ration... 9.22 2.44 44.93 15.82 

Keducing the fat to its value in starch (250), we 
get the value of the digestible non-nitrogenous con- 
stituents in the diet : 

Fat, 2.44 lbs. equal to 5.95 lbs. 

Carbohydrates 44,93 lbs. 

Fibre 15.82 lbs. 

Total value equal to 66.70 lbs. 

From which we find by the usual rule (257) that the 
albuminoid ratio of the mixed diet is 1 : 7.23.* 

263. The following table gives the albuminoid ra- 
tio of various foods, calculated from the digested por- 
tions only. The first column gives the ratio as deter- 
mined by calculations made on the supposition that 
all the nitrogenous substances in the food are true al- 
buminoids. The second column gives the ratio as de- 
termined by estimating only the true albuminoids. 
The figures given in the first column for cakes and 
grains are nearly correct. The true ratio for turnips 

*It will be noticed that this calculation is made on the sup- 
position that all the nitrogen is in albuminoids, and the ratio 
thus obtained is therefore rather above the truth. 



128 



SCIENCE IN FARMING. 



would probably be about 1 : 12, and of wheat straw 
not more than 1 : 100; for clover hay about 1 : 9. 

ALBUMINOID RATIO OF THE DIGESTED PORTION OF FOODS. 

Reckonins: all Ni- Reckoning on- 



Name of Food 



trogenoiis matter 
as albuminoids. 



ly the true 
albuminoids. 



Cotton cake decorticated 1 

Cotton cake undecorticated 1 

Linseed cake 1 



1.5 

1.8 

2.3 

2.4 

2.9 

4.2 

5.5 

7.() 

9 

5.9 



1 



1 : 12.4 



.•^1 
17 



8 



Beans 1 

Peas 1 

Wheat bran 1 

Oats 1 

Barley 1 

Indian corn 1 

Clover hay 1 

Meadow hav 1 

Turnips . . /. 1 : 6.2 

Mangels 1 : 8 

Potatos 1 : 10. () 

Wheat straw 1 : 64.4 

264. The same food may have a different albumi- 
noid ratio wiien fed to different animals, as one may 
digest a larger proportion of the albuminoids, and the 
other a larger proi)ortion of the carbohydrates. In 
one experiment a horse and a sheep were fed on the 
same meadow hay. The portion of the hay digested 
by the horse had an albuminoid ratio of 1 : 6.7, while 
the portion digested by the sheep had a ratio of 1 : 9.1. 
This difference was due to the fact that the horse di- 
gested as large a proportion of the albuminoids in the 
hay as the sheep, but the latter animal digested a 
larger proportion of the carbohydrates and crude fibre. 



CHAPTER X. 



SCIENCE IN FEEDING. 



§ 1. General Princij^les. 

265. The practical objects to be attained in leeding 
are: 

1. To cause growth — development of bone and mus- 
cle — in the young animal. 

2. The production of milk. 

3. The production of fat. 

4. To furnish material from which the animal can 
derive energy to be employed in useful work. 

A fifth might be added — namely, the production of 
manure, but this will be considered in the next 
chapter. 

266. While food is being supplied for these pur- 
poses, a sufficient amount must also be furnished to 
rei)air the wastes of animal substance (206), maintain 
the heat of the body, and furnish the energy required 
in the vital processes (212). 

267. We have seen (203) that the plant is the ma- 
chine by which inorganic substances are converted 
into forms that can be used by the animal. To the 
farmer, the animal is only a machine for the conver- 
sion of vegetable substances into flesh, fat, milk, wool 

etc., and for the development into useful work of the 
9 



130 SCIENCE IN FARMING. 

energy which the plant has obtained from the sun 
and stored in the food. 

268. If a steam engine attached to a mill requires 
20 lbs. of coal per hour to overcome the resistance of 
the machinery and only that amount is supplied, no 
useful work can be accomplished. If the supply of 
coal is increased to 30 lbs. per hour, the energy de- 
rived from the 10 lbs. added would be available for 
grinding. If 40 lbs. per hour is supplied, the available 
power will be that of 20 lbs. of coal. Thus by the last 
increase of 10 lbs. the work which can be accom- 
plished is doubled. 

269. The same principle applies to the science of 
feeding. If an animal which requires 20 lbs. of food 
per day to repair the waste of tissue and carry on the 
vital processes receives only that amount, no part of 
this food can be applied to growth, production of fat 
or milk, or in useful work. If a larger quantity of 
food is supplied, the additional food can be used for 
profitable increase. 

270. The animal is, in fact, engine and mill com- 
bined. Into the same hopper is put the grist to be 
ground and the fuel to drive the engine. Only that 
which is furnished in excess of the amount required 
to keep mill and engine running and in repair pays 
any profit to the owner. Of this excess part is ground 
up and worked over into profitable forms, and part is 
used to supply the additional energy needed for the 
purpose. 

Underfeeding is therefore extravagance. 

271. Adaptation of Foods. — It is not only necessary 
that the animal should have sufiicient food, but it 
must be adapted to the object desired. If the food 
supplied to a growing animal is composed chiefly of 



FEEDING. 131 

non-nitrogenous matters, these cannot be converted 
into muscle, and either growth will be checked or an 
excess of food must be supplied — and a portion of the 
carbohydrates be wasted. If on the other hand the 
food contains a larger proportion of albuminoids than 
is needed, while the animal will not suffer, as the al- 
buminoids will meet all its needs (210), yet as they 
are much more expensive than carbohydrates, the 
farmer's profits will be greatly diminished. 

272. Effects of Exercise.— We have seen that the 
physical energy in the animal is derived from the 
combustion of the carbon of the food in the blood 
(211). The greater amount of physical effort required 
the greater amount of the food consumed will be used 
for this purpose. 

It has been ascertained by experiment that a man 
when doing a fair day's work, gives off from his lungs 
one-third more carbonic dioxide than in an equal time 
when at rest, which proves that when at work one- 
third more food was burned in the system. 

Hence all unnecessary exercise on the part of an 
animal causes a waste of food. When cows are 
driven long distances to and from pasture, are com- 
pelled to roam over closely cropped fields in^search 
of food, or worried by flies, or chased by dogs and 
boys, the farmer may know that the energy^thus^ex- 
pended is obtained by the combustion of food that 
would otherwise be converted into milk and butter.* 



*The greatly increased production of butter and cheese 
claimed by the advocates of soiling, is partially explained by 
tlie fact just given. The cows kept in a quiet and'comfortable 
stable, protected from annoyance by flies and spared all un- 
necessary exertion, can put into the pail a quantity of butter, 
that, were they roaming over a large pasture and fighting flies, 
they would be obliged to burn" for the production of physical 



132 SCIENCE IN FARMING. 

273. Effects of Cold. — Exposure to cold results in 
loss to the farmer in much the same manner as excess 
of exercise. The animal heat must be maintained 
and food will be burned in the system in proportion 
to the demand for this purpose. Food which the an- 
imal should be manufacturing into fat, flesh or milk, 
is burned to keep the animal warm. A farmer would 
be considered extravagant who would put up a stove 
to warm his stable and feed the fire with butter, but 
when he leaves his cows exposed to cold and storms, 
they have to keep warm by burning the butter which 
would otherwise go into the milk i3ail. 

274. In some experiments with sheep made to as- 
certain the amount of food required to produce one 
pound increase of live weight, it was found that 150 
lbs. of turnips were required to produce this amount 
of increase when fed to sheep which had no protec- 
tion from storms and cold, but that the same result 
was obtained by feeding 100 lbs. when the sheep were 
protected. 

275. The Kansas State Board of Agriculture re- 
cently made some experiments in fattening pigs. A 
number were put in pens and fed and treated alike, 
with the exception that part of the pens were in the 
basement of a barn and iDart were out of doors. It 
was found that one pound of increase was made from 
5.15 lbs. of corn fed to the pigs in the barn, but that 

energy. Men who have had no experience in soiling, often 
wonder how it is possible that the food grown on an acre 
should produce any more milk and butter when cut and fed to 
animals in the stable, than when the same animals gather it 
for themselves. They do not see the butter burned to enable 
the cow to wander after her food, and fail to appreciate that it 
is burned as truly as if put into the fire-box of an engine. 



FEEDING. 133 

5.48 lbs. corn were required to make one pound of 
increase in the pigs fed outside. 

Too great heat is also wasteful, as it occasions per- 
spiration and food must be consumed in its evapora- 
tion. 

276. Effect of Water in Food. — A certain amount of 
water is necessary to the life of the animal, but if an 
excess is contained in the food waste will be oc- 
casioned, as the water must all be warmed to the 
temperature of the animal and a part must be evapo- 
rated through the skin. Considerable food must be 
burned to produce the heat thus required. 

277. The proper proportion of water is, for sheep 
about two parts to one of dry substance ; for cattle, 
four parts to one. Cows giving milk require a still 
larger proportion of water. 

278. In feeding grains and dry fodder^there is lit- 
tle probability of supplying too much water, but in 
feeding roots alone the quantity of water is liable to 
be greatly in excess of the animal's requirements. 
When an animal is fed exclusively on turnips, a large 
part of the dry substance consumed will be used in 
raising the temperature and evaporating the surplus 
water. 

279. Hence, roots should usually be fed in connec- 
tion with dry food, and when fed in this manner, will 
give much better results than when fed alone. 

§ 2. Proper Food for the Young Animal. 

280. The chief object of the food supplied to the 
young animal is to produce bone and muscle, as the 
production of a large amount of fat is not desirable. 
The food, therefore, should be rich in albuminoids, 
phosphoric acid and lime. The milk — called colos- 



134 SCIENCE IN FARMING. 

trum — which Nature furnishes for the young animal 
at birth, is exactly fitted for the purpose designed. 
The following table gives the analysis of the colos- 
trum of the cow : 

Water 716 

Albuminoids 207 

Fat 34 

Sugar 25 

Ash ^ 18 

1,000 

The albuminoid ratio is about 1 : 0.5. The ash, 
which is also in large proportion, is principally calcic 
phosphate. This food is therefore specially adapted 
for producing bone and muscle. During the first 
few days of its life the animal takes but little ex- 
ercise ; consequently the amount of carbonaceous 
food required is not large. The character of the milk 
soon changes, as the needs of the animal change. The 
milk contains more fat and sugar, and less albumi- 
noids and ash. The following is the average compo- 
sition of cow's milk : 

Water 870 

Albuminoids 40 

Fat 37 

Sugar 46 

Ash 7 

1,000 
The albuminoid ratio is now only 1 : 3.3. 
The composition of milk gives the key to the proper 
food for the growing animal. 

281. It should be readily digestible and contain a 
fair proportion of fat. Carbohydrates can take the 
place of fat; but as 2.44 lbs. carbohydrates are re- 
quired to equal 1 lb. of fat, a less bulk of carbona- 
ceous food will be required when fat is provided, and 
the animal will thus be able to consume more albu' 



FEEDING. 135 

minoids, which are essential for the development of 
bone and muscle. The food must also contain a due 
proportion of phosphoric acid and lime. 

282. By reference to the table of foods (230), it 
will be seen that young clover and grass are rich in 
albuminoids. They also contain a considerable per- 
centage of phosphates, and therefore form a suitable 
diet for the growing animal. Bran makes a good ad- 
dition to such a diet, and a little linseed cake will 
supply the fat and albuminoids. 

283. Many of our best farmers have adopted the 
plan of putting their growing pigs on grass or clover 
pastures, and feeding but moderately with corn. 
This enables the pig to grow and develop a large, 
bony and muscular carcass, with capacious digestive 
organs. When the time arrives for fattening such an 
animal, it can consume large quantities of food, and 
produce a proportionately large amount of fat. 

284. The proper albuminoid ratio for a growing 
animal is 1 : 5 to 1:7. When all the nitrogenous 
matter has been reckoned as albuminoid, in determin- 
ing the ratio, it should not be less than 1 : 5. 

§ 3. Proper Food for Producing Milk. 

285. As milk contains a large proportion of albu- 
minoids and phosphates, the food must contain enough 
of these substances to meet the demands for milk in 
addition to what is required to supply the wastes of 
tissue. If the food does not contain enough of these 
substances, the flow of milk will be diminished, or 
the cow must use her own tissues for its production. 
The food should also contain some readily digestible 
fat, as we have seen that this is contained in milk in 
considerable quantity (280). 



136 SCIENCE IN FARMING. 

286. If a food is deficient in albuminoids, the cow 
may be fed all she can eat, and yet be unable to yield 
a liberal supply of milk. 

287. As the bulk which a cow can eat is limited, 
the food should be tolerably concentrated ; otherwise 
it will not be possible for her to obtain a sufficient 
amount of nutritive substances in the quantity she is 
able to eat 

288. For example. By reference to the table in 
paragraph 239, it will be seen that a ton of wheat 
straw contains only 12 lbs. of digestible nitrogenous 
matter. Not more than half of this is in the form of 
true albuminoids. As 25 lbs. of milk contain about 1 
lb. albuminoid, it would be necessary for a cow fed 
on wheat straw alone, to consume (in addition to the 
amount required to repair the wastes of her tissues) 
333^ lbs. straw in order to produce 25 lbs. of milk. It 
is true that a cow could not eat such a quantity of 
straw in a day, but it would be as possible for her to 
do so as it would be for her to give a liberal flow of 
milk on such a diet. This explains why farmers who 
winter their cattle at the straw stack find it impossi- 
ble to make butter in winter.* 

289. Pea and bean meal, linseed and cotton cake 
are rich in albuminoids. Bran and clover are also ni- 
trogenous foods and contain a considerable x)roportion 
of phosphates. Mangels supply valuable carbohy- 
drates. A diet of good clover or meadow hay, with 



*A cow could hardly keep alive, much less give milk, fed on 
pure wheat straw. Practically a straw pile always contains a 
little grain and some other substances, and the cattle " pick 
up" a little food besides. The usual condition in spring of 
cattle wintered at the straw stack, is, however, a sufficient evi- 
dence of the correctness of the scientific principles that have 
been laid down. 



FEEDING. 137 

mangels, bran and a small amount of linseed or cot- 
ton cake, bean or pea meal would be a good milk 
diet from a scientific stand-point, and practical expe- 
rience has approved it. 

290. The value of young meadow grass as a milk 
diet is well known. The fact that cows on pasture 
decrease in flow of milk as the season advances, is 
also a familiar one. This is caused by the decrease 
of albuminoids in the older grass. By reference to 
the table in paragraph 243, it will be seen that 100 
lbs. of hay, cut May 14th, contained a little over 
11 lbs. of digestible albuminoids, while the same 
quantity cut June 26th, contained but 4 lbs. The 
cow cannot eat more grass in summer than in spring, 
and therefore if at each period she has all the grass 
she can eat, she will by June 25th get but four- 
elevenths as much albuminoids as she would May 
14th.* 

291. Wolf gives the albuminoid ratio of a milk 
diet as 1 : 5, reckoning all the nitrogenous matter as 
albuminoids. Reckoning only the true albuminoids, 
a ratio of 1 : 6 or 1 : 7 will be sufiicient. 

292. Meadow grass cut May 14th has a ratio of 
1 : 4.14 (reckoning all nitrogenous matter). That cut 
June 26tli has a ratio of only 1 : 10.76. The first, there- 
fore is a rich milk diet, while the latter falls far below 
the requirement. 

293. Analysis of aftermath hay shows that while 
it is no richer in albuminoids than the first crop, it is 
very considerable richer in fat. The following table 

*This further explains the advantages claimed by the advo- 
cates of soiling. Under this system the cattle are kept con- 
stantly supplied with fresh young grass and fodder, cut at the 
time when it is richest in nitrogenous constituents. 



138 SCIENCE IN FARMING. 

gives the number of pounds of food constituents in a 
ton of aftermath hay : 

Water 237.4 lbs. 

Nitrogenous matter 196.8 lbs. 

Soluble carbohydrates 845.0 lbs. 

Fat 136.8 lbs. 

Crude fibre 395.4 lbs. 

Ash 188.6 lbs. 

2,000.0 lbs. 

Such hay if fed with sufficient nitrogenous food to 
secure a proper albuminoid ratio, would make a bet- 
ter milk diet than the first crop. 

294. Mr. T. Horsfall, of England, made some of 
the most complete experiments on the diet of milk 
cows. He first calculated a diet from scientific prin- 
ciples, and then applied to this the test of practical 
experiment. The ration for each cow per day con- 
sisted of: 

]\Ieadow hay 9.33 lbs. 

Rape cake 5. lbs. 

Malt combs 1.5 lbs. 

Wheat bran 1.5 lbs. 

Beans 1.5 lbs. 

Green fodder .34. lbs. 

Oat straw 8.33 lbs. 

Bean straw 2. lbs. 

Total 63.1 6 lbs. 

The rape cake, malt combs, wheat bran, beans and 
bean straw made this a highly nitrogenous diet, the 
albuminoid ratio being 1 : 5.4. The rape cake fur- 
nished a considerable quantity of fat. In some parts 
of the country rape cake and malt combs cannot be 
obtained. Linseed or cotton cake can be substituted, 
and a diet fully equal to Horsfall's be obtained. If 
neither of these can be had, an approach to the ration 
could be made by increasing the proportion of bran 
— using clover or Hungarian grass and some corn 
meal. 



FEEDING. 139 

Mr. Horsfall's cows on this diet gave a large quan- 
tity of milk, of which 16 quarts yielded from 24 to 28 
ounces of butter. And the cows gained in weight. 

§ 3. The Fattening Animal. 

295. The chief constituent in the increase in a fat- 
tening animal is fat. In experiments at Kothamsted 
it was found that the increase of weight in a fattening 
sheep consisted of: 

Water 22.0 

Nitrogenous matter 7.2 

Fat 68.8 

Ash 2.0 

The increase contained nearly ten times as much 
fat as muscle. 

296. Theoretically, therefore, the fattening animal 
requires a diet containing but a small proportion of 
albuminoids. Practically, however, it is found that 
when the ratio falls as low as theory would indicate 
could be used, the digestibility of the food is im- 
paired and the health of the animal suffers (247). 

297. The albuminoid ratio* of food for a fattening 
animal has been ascertained to be : 



For cattle -, 1 

For sheep 1 

For pigs 1 



10 
9 

7 



298. A diet richer in albuminoids may often be 
used with advantage when not too expensive. Food 
excessively rich in albuminoids, as cotton cake, is 
liable to produce disease if fed in large quantities. 
Such substances should always be fed moderately 
and in connection with other foods. 

299. Experiments in Fattening. — The following ta- 
ble shows the result of some experiments made by 

^Reckoning only the true albuminoids. 



140 SCIENCE IN PARMINa. 

Messrs. Lawes & Gilbert, of Kothamsted, England, 
for the purpose of determining the amount of food 
required to produce an increase of a pound of live 
weight, and the relative capabilities of different ani- 
mals for converting food into meat. In the experi- 
ment, the oxen and sheep were fed on linseed cake, 
clover hay and sweedes ; the pigs on barley meal : 

RESULTS OBTAINED PER HUNDRED POUNDS LIVE WEIGHT PER WEEK. 

Oxen. Sheep. Pigs. 

Dry food received per week per 
hundred pounds Hve weight 12.5 16.0 27.0 

Which contained of digestible sub- 
stance 8.9 12.3 22.0 

Amount of food expended per week 
in production of heat and energy 
for each 100 lbs. live weight 6.86 9.06 12.58 

Gain in live weight per week for 
each 100 lbs. of live weight of 
animal 1.13 1.76 6.43 

The student will understand from the above table 
that an ox weighing 1,000 lbs. consumed per week 
food containing 125 lbs. of dry substance, of which he 
digested 89 lbs. 68.6 lbs. of this was used in the pro- 
duction of heat and energy, and 11.3 lbs. stored as in- 
crease in live weight. The remainder of the digested 
matter was expended in repairing the wastes of the 
body. 

300. The table also shows that a sufficient number 
of pigs to weigh 1,000 lbs consumed per week food 
containing 270 lbs. dry substance, of which they di- 
gested 220 lbs. 125.8 lbs. of the digested matter was 
used in the production of heat and energy, 64.3 lbs. 
stored up as increase, and the remainder expended in 
repairing waste of tissue. 

301. These experiments show that the pig eats more 
in proportion to his weight than the ox, but he also 



FEEDING. 141 

makes a larger amount of increase in proportion to 
food consumed. 

KESULTS OBTAINED PER HUNDRED POUNDS DRY FOOD USED. 

Ox. Sheep. Pig. 
Received by animal 100 100 100 

Digested 72.2 76.9 81.5 

Used for heat and energy 54.9 56.6 46.6 

Laid up in increase 9 11 23.8 

By the term 100 lbs. dry food is meant an amount of 
food containing 100 lbs. dry substance. 

302. It will be noticed that the pig digested a 
larger proportion of his food than the ox. This was 
not due to the better digestive powers of the pig, but 
to the fact that his food contained a larger proportion 
of digestible material. Calculating therefore only on 
the digestible portion of the food, we get the follow- 
ing table, showing the amount of increase in live 
weight produced from 100 lbs. digested dry substance 
— that is, from an amount of food containing 100 lbs. 
of digestible dry substance : 

Ox. Sheep. Pig. 
Increase in live weight per 100 lbs. 
digested food 12.7 14.3 29.2 

It will be seen that the pig produced a far greater 
amount of increase from a given amount of digestible 
food than either the sheep or the ox, showing that he 
is the most profitable machine which the farmer can 
use for the conversion of his crops into meat. 

303. The table in paragraph 299 shows that even 
in these experiments, where the animals were care- 
fully treated, and no unnecessary food expended in 
the production of heat and energy, the amount of 
food consumed for this purpose was far greater than 
that stored in the increase. 

304. The fact that the pig uses a larger proportion 



142 SCIENCE IN FARMING. 

of the food he consumes in production of increase 
than the ox, and less for heat and energy, explains 
the reason why he requires a diet richer in albumin- 
oids. 

305. The fattening animal does not make the same 
rate of increase, nor yield the same profit on food 
consumed during the whole fattening period. As the 
animal increases in size and weight, it can eat less 
food in proportion to its weight, and probably digests 
a smaller proportion of what it does eat. It also uses 
a larger proportion of the digested food for production 
of heat and energy and repair of waste. 

306. An experiment was made at Rothamsted with 
16 pigs, averaging 135.8 lbs. at the commencement of 
the fattening period, and 276.3 lbs. at its completion. 
The food consisted of 7 lbs. pea meal per day for each 
pig, with all the barley meal in addition that they 
Avould eat. The pigs were fed for ten weeks and 
weighed every two weeks. The following table gives 
the result. The number of pounds of food refers to the 
food in its ordinary condition — not to the dry sub- 
stance: 

Food con- Food consum'd Food consum'd 
sumed per per 100 lbs live to produce 100 





head. 


weight. 


lbs increase 


First two weeks . . . 


. 60.1 lbs. 


39.7 lbs. 


386 lbs. 


Second two weeks . 


. 67.5 lbs. 


36.7 lbs. 


388 lbs. 


Third two weeks . . 


. 66.4 lbs. 


30.9 lbs. 


502 lbs. 


Fourth two weeks . 


. 66.0 lbs. 


27.4 lbs. 


511 lbs. 


Fifth two weeks . . . 


. 69.6 lbs. 


26.3 lbs. 


618 lbs. 



Average for ten w'ks 65.9 lbs. 32.0 lbs. 469 lbs. 

307. During the first two weeks 3.86 lbs. food pro- 
duced 1 lb. increase ; but during the last two weeks 
it required 6.18 lbs. to produce that amount. Calcu- 
lating that 90 per cent of the increase was butcher's 
,(DarQass, it required du^g the first two weeks only 



FEEDING. 143 

4.29 lbs. food to produce a pound of pork ; but during 
the last two weeks 6.88 lbs. to produce that amount. 
The pork made during the last two weeks therefore 
cost 60 per cent more than that made the first two. 

308. In experiments made in feeding pigs in the 
United States, it was found that 5.33 lbs. corn was re- 
quired to make 1 lb. increase in live weight, while in 
the English experiment just given, the average for 
the whole period was 1 lb. increase from 4.69 lbs. food. 
The difference in favor of the English experiment 
was probably due to the fact that the food used — a 
mixture of pea and barley meal — had a much higher 
albuminoid ratio than corn. 

309. Corn does not contain a sufficient proportion 
of albuminoids to make a perfect diet for fattening 
pigs. Consequently the addition to a corn-diet of a 
small amount of some highly nitrogenous food, as 
linseed cake,* or bean or pea meal, greatly increases 
the value of the whole food. 

310. Skim milk is a highly nitrogenous food. Its 
percentage composition is about : 

Water 90. 

Albuminoidst 3.7 

Fat 0.8 

Sugar 4.8 

Ash 0.7 

157.4 lbs. skim milk contains as large an amount of 
albuminoids as a bushel of corn. We have seen that 
a pig requires a diet having an albuminoid ratio of 
1 : 7, and that the ratio of corn is only 1:9. If a 
pound of skim milk is fed with every pound of corn, 

*Linseed cake can only be fed in small quantity, or it will 
injure the flavor of the pork. 
tThe nitrogenous matters in milk are all true albuminoids 



144 SCIENCE IN FARMING. 

the albuminoid ratio of the whole diet would be 1 : 6.4 
— a ratio sufficient to secure the best results.* 

311. The entire increase of live weight in a fatten- 
ing animal is not useful carcass. As the animal grows 
the digestive organs also grow. The increase of offal 
is not as great proportionally as the increase of butch- 
er's carcass, and consequently the highly fattened 
animal contains a larger percentage of carcass and 
less percentage of offal than the animal in " store " 
condition only. 

312. In fattening a sheep, from 68 to 77 per cent of 
the increase is carcass. 

313. Of the fatted animal, about 60 per cent of the 
fasted live weight is carcass in the ox, 58 per cent in 
the sheep and 83 per cent in the pig. 

§ 4. The Working Animal, 

314. A working animal, if it has been properly 
grown, will contain a large amount of muscular sub- 
stance and a comparatively small proportion of fat. 
To replace the waste of this muscular tissue will re- 
quire a fair amount of albuminoids in the food. Be- 
yond this, carbohydrates and fat meet the require- 
ments of the working animal. It has been found that 
an albuminoid ratio of 1 : 9 is sufficient for an adult 
horse at work. 

315. It would seem that a horse not at work would 
require about as large an amount of albuminoids as a 
working horse, but a smaller amount of carbohy 

*This explains why persons who have but one or two pigs 
and give them the skim milk and scraps from the table, are so 
successful. The small quantity of food rich in albuminoids 
added to the corn, raises the character of the whole diet, and 
better results are obtained from all the food given. 



J^EEDiNd. 145 

drates, and that therefore the albuminoid ratio of his 
diet should be higher. 

316. In growing an animal intended for work, the 
object is to produce the largest possible development 
of muscle, and but a small development of fat. There- 
fore the food for the young animal intended for work 
should be rich in albuminoids — bran, oats, peas, beans, 
clover, etc. 

§6 . Summary. 

The only profit which the farmer can secure in 
feeding, is that from food supplied in excess of the 
amount required to keep the animal alive and in 
health. 

It is not only necessary that the food be sufficient 
in quantity, but its character must also be adapted to 
.the purpose desired. Lack of care and judgment in 
this respect is likely to result in injury to the animal, 
waste of some of the food constituents supplied, or the 
use of unnecessarily expensive foods. 

In arranging a mixed diet, the effect of the mixing 
upon the digestibility of the food must be carefully 
considered, otherwise, much of the food supplied may 
remain undigested, causing waste and loss. 

The greater the amount of food, a fattening animal 
can be induced to eat and digest, the greater will be 
the profit obtained in j^roportion to the amount of food 
consumed. Therefore the flavor of the food, and the 
degree in which it is relished by the stock, have an 
important influence on the profits of feeding. 

Exertion, and exposure to cold require a large 

consumption of food which gives no returns in flesh 

or fat, therefore, economy requires that fattening stock 

be protected from the weather, and spared all un- 

necessarv exercise. 
10 



146 Science in FARMiNa. 

The increase of weight j)roduced from a given 
amount of food is greater in the young animal than in 
the old, and greater in the beginning of fattening than 
towards its close. Therefore, a careful estimate should 
be made of the cost of the food and the value of the 
meat produced, so that the farmer may know at what 
time to sell his stock in order to secure the largest 
profit on food used. 

In fattening pigs, improvement in their health, and, 
therefore, in the iDrofit of the farmer, has been secured 
by keeping them supplied with a mixture of 20 lbs. 
sifted coal ashes, 4 lbs. salt, and 1 lb. superphos- 
phate of lime. 



CHAPTER XL 



SCIENCE IN FERTILIZERS. 



§ 1. QenQval Principles, 

317. A fertilizer is a substance which, if added to 
the soil, will increase its capacity for the production 
of a crop. The science of fertilization includes all 
methods of rendering the soil more productive. 

318. The production of a good crop depends on the 
soil and the season. Over the former, only, the farmer 
has control, and it is his business to provide a condi- 
tion of soil that will secure the largest crop the sea- 
son is capable of producing. 

The conditions of soil necessary for this are : A 
sufficient amount of plant food, in a form that can be 
used by the crop; 

Such a mechanical condition of the soil as will en- 
able the roots of the plants to reach and use the avail- 
able plant food present. 

319. Nature and Cultivation. — We have seen (145) 
that in a state of nature the amount of plant food in 
the soil tends continually to increase. Under cultiva- 
tion where crops are carried ^iway, the amount must 



14S SCIENCE IN FARMING. 

decrease, unless in some manner the plant food taken 
awaj^ from the soil is restored. 

320. Favorable mechanical conditions of the soil 
are obtained by cultivation, drainage, and sometimes 
by plowing under green crops (See "Soils," sections 
5, 6, and 7). 

321. Plant food in the soil is rendered available by 
drainage, cultivation, the use of lime, bare fallow, 
and by plowing under green crops (See " Soils," par- 
agraphs 161-163). 

322. The amount of plant food in the soil is in- 
creased by the addition of manures. 

323. The methods necessary to secure favorable 
mechanical conditions of the soil also tend to increase 
the amount of plant food by favoring absorption from 
the air, and to render that which is present available, 
by favoring nitrification and the solution of mineral 
substances. 

324. The methods necessary to render plant food 
available, also usually improve the mechanical condi- 
tion of the soil, and by favoring absorption, tend to 
increase the total amount of plant food in the soil. 

325. The addition of manures frequently improves 
the mechanical condition of the soil, and may also, by 
starting chemical action, render the plant food al- 
ready present, more available. 

It is therefore impossible to draw a strictly accu- 
rate line between these different methods. The 
farmer must usually employ all three, and in order to 
attain the best results, their judicious combination is 
necessary. 

The methods of improving the mechanical condi- 



FERTILIZERS. 149 

tion of soils have been considered in chapter six. 
§ 2. Bendering Plant Food Available. 

326. Bare Fallow. — This is one of the oldest meth- 
ods of improving the condition of soils. It is often 
called " resting the land," but the term is unscientific 
and misleading. In a bare fallow the land is allowed 
to remain one season without a crop, and is contin- 
ually cultivated in order to keep down weeds, and ex- 
pose the soil to the action of the air. Except by fa- 
voring the absorption of ammonia from the air, it does 
not increase the amount of plant food, but by favor- 
ing oxidation, a portion of the mineral substances is 
rendered soluble, and by nitrification the nitrogen 
contained in the humus of the soil is converted into 
nitric acid. Under favorable circumstances, a large 
amount of nitrogen — sometimes as much as 35 to 55 
lbs. per acre — will be converted into nitric acid, and 
the soil be able to produce a double crop the year suc- 
ceeding the fallow. 

In some experiments at Rothamsted, one part of a 

field was cropped with wheat four years in succession; 

another part was cropped and fallowed alternately. 

The soil was the same and no manure was used. The 

following table gives the yield per acre for the four 

years, the field that was cropped continuously being 

marked No. 1, and the field fallowed each alternate 

year. No. 2 : 

Field No. 1. Field No. 2. 

First year 15.87 bn. Fallow 

Second year 13.81 bu. 37 bu. 

Third year 15.81 bu. Fallow 

Fourth year 21.06 bu. 42 bu. 

Total in four years 66.55 bu. 79 bu. 

In this experiment the field that was alternately 



150 SCIENCE IN FARMING. 

cropped and fallowed, produced in the four years a 
total of nearly 12^ bushels per acre more than the 
other. As, in this case, one-half the seed and nearly 
one-half the labor of harvesting were saved, the fal- 
lowed field was the more profitable. 

Producing a heavy crop alternate years by means 
of a bare fallow, simply draws on the supply of plant 
food in the soil. 

If heavy rains fall on a bare fallow, much, or in 
some cases all, of the nitric acid formed may be 
washed out. The constant use of the bare fallow as 
a means of securing large crops therefore tends, un- 
der ordinary conditions of soil and climate, to the ul- 
timate exhaustion of the nitrogen in the soil. 

327. Lime. — Tlie principal effect of the application 
of lime is to favor the decomposition of humus in the 
soil. The amount of plant food furnished is unim- 
portant, as nearly all soils contain sufiicient to 
supply the needs of any ordinary crop. The use of 
lime is therefore classed among the methods adopted 
for rendering plant food already present in the soil 
available. Its principal value for this purpose is on 
soils that are over-rich in humus (174). The persis- 
tent use of lime without other manures, therefore, 
tends to greatly reduce the total amount of nitrogen 
in the soil. While valuable when properly used, 
many farms have been almost ruined by its injudi- 
cious application. Lime is also sometimes useful on 
clay soils, by improving their mechanical condition 
(170). In this manner it may not only render a clay 
soil more easy to Avork, but also increase its capacity 
for absorbing and retaining fertilizing elements. 

328. Green Manuring. — Growing green crops and 
plowing them imder is properly classed as one of the 



FERTILIZERS. 151 

methods of rendering plant food available. It is true 
that a large portion of the crop was obtained from tlie 
air, but that portion is not of value as plant food in 
the soil. The nitrogen* and mineral elements in the 
plant were obtained from the soil, and the actual 
quantity of these elements in the soil is, therefore, 
not increased. 

329. Green manuring renders the plant food in the 
soil available : 

By gathering that which is already present, form- 
ing it into organic substances which are left near the 
surface, and as they decay, give up to the succeeding 
crop that which they have gathered. 

By taking up the nitric acid as rapidly as formed 
by nitrification, and thus preventing it from washing 
out in the drainage water. 

By shading the soil, keeping it moist, and loose, and 
thus providing the circumstances favorable for nitri 
fication.f 



*The leaves of plants absorb from the atmosphere some am- 
monia (142), and the nitrogen contained in this is gained by 
the soil when the crop is plowed under. The quantity thus 
obtained is, however, so small and so uncertain that it cannot 
be taken into consideration in practical estimates. 

fNumerous experiments appear to indicate that under cer- 
tain circumstances the free nitrogen of the air which is con- 
tained in the pores of the soil, maj^be oxidized into nitric acid. 
The circumstances necessary are, a porous soil, rich in humus, 
a certain amount of moisture, warmth, and the presence of 
some base with which the nitric acid can combine as rapidly 
as formed. The presence of ferric oxide in considerable quan- 
tity seems to aid the action by catalysis (122). Should futur-.? 
experiments demonstrate that this oxidation of free nitrogen 
can be accomplished to any considerable extent under the in- 
fluences which the farmer can control, the present views of the 
operation of green crops will require serious modification. It 
will then appear possible, by green manuring, not only to 
change the nitrogen in the soil into more available forms, but 



152 SCIENCE IN FARMING. 

By attacking plant food existing in the soil in forms 
of combination not available for other crops. Legu- 
minous crops (clover, peas, beans, etc.) appear to 
have the power of feeding on nitrogenous substances 
in the soil in forms that are not available for cereal 
crops. This nitrogen it leaves in forms of combina- 
tion that readily undergo oxidation with production 
of nitric acid. Hence clover, even when the crop is 
cut for hay and seed, leaves in the roots and stubble 
a large amount of plant food that can be used by the 
succeeding crop. 

8 3. Manures. 



330. The plant takes from the soil a large number 
of substances, but in practice only three have to be 
considered. These are : 

Nitrogen. 

Phosphoric acid. 

Potash. 

The other mineral elements of plant food are equally 
essential, but they are usually contained in the soil 
in sufficient quantity, and most manures that contain 
nitrogen, phosphoric acid and potash, also contain 
these other substances. These three are the ones to 
be considered in estimates of the fertility and exhaus- 
tion of soils and in the valuation of manures. 

331. We have seen (158) the amount of these sub- 
stances in a very fertile soil. The following table 



also to add to its quantity. With our present knowledge on 
this subject, however, it will not be safe for the farmer to de- 
pend on increasing his store of nitrogen by this means ; what- 
ever future discoveries may be made, the wise farmer will still 
carefully save and return to his soil all waste plant food. 



FERTILIZERS. ^^^ 

shows the amount taken from an acre by an average 
crop: 

O 00 ^ 03 

20 bushels wheat 22 lbs. 9.5 lbs. 6.4 lbs. 

2000 lbs. straw Mi^ _5,2Jlbs^. llJBlbs. 

Total crop 31.6 lbs. UJ^lbs. lU^s. 

30 bushels barley 26.2 lbs. 12.11bs 7.3 lbs 

18000 lbs. straw 9 1^^- _Mi£i' 17^41DS. 

Total crop 35j^lbs. 15JJbs. 22^1bs. 

30 bushels oats 25.3 lbs. 7.9 lbs. 5.7 lbs. 

1800 lbs. straw _MJbs. _4^1bs^, 18wlbs. 

Totalcrop oMJ^s. 12^1bs. 2JL4jbs. 

20 bushels rye 10.7 lbs. 9.4 lbs. 6.3 lbs. 

32401bsstraw 13,0]bs. J^^Sjbs. 2£,2Jbs. 

Totalcrop 3J£]b8. 16^1bs. .3^5Jbs. 

50 bushels Indian corn .... 41.4 lbs. 128 lbs. 10.8 lbs. 

8000 lbs. cornstalks 38.4 lbs. 42 4 lbs. 7b.h lbs. 

Totalcrop 7j)£lbs. oo^lbs. 87.6 lbs. 

2 tons meadow hay 6£0Jbs, 15£lbs. 67.2 lbs. 

2 tons clover hay 70Jbs, 22,4Jbs 78.0 lbs. 

15 tons turnips 54.0 lbs. 18 lbs. 87.0 lbs 

9000 lbs. tops 38.6 lbs. 8.4 lbs. 31.7 lbs. 

Totalcrop 92^6Jbs. 2^^^^^ USJJbs, 

20 tons mangels 76 lbs. 28.0 lbs. 156.0 lbs. 

leOOOlbs.tops 44Jibs. 13_3]bs. . 62./ lbs. 

Totalcrop 120^1^ MM BMMl 

100 bushels potatos 20.4 lbs. 10.8 lbs. 33.6 lbs. 

20001bshaulm .0-3 lbs. _3^1bs. ^bs^, 

Totalcrop '^nbs. 13£lbs. 41£jbs. 

332. It would require a great many years to re- 
move all the nitrogen, phosphoric acid and potash 
from a soil (even were it possible to continue to grow 
crops until the whole amount was exhausted) but that 



154 SCIENCE IN FARMING. 

which is ill an avaihxble condition may be exhausted 
in a few years. 

333. It is also necessary in order to produce a full 
crop, that the soil should contain considerably more 
of these substances in an available form than the crop 
will require, for no plant can gather all the available 
plant food in the soil. Thus we see that a crop of 
wheat of 20 bushels to the acre, contains only about 
32 lbs. of nitrogen, but such a crop cannot be grown 
unless the soil contains at least 65 lbs. available 
nitrogen. 

334. The means employed to supply the required 
available plant food, and prevent the deterioration of 
the soil by too heavy drafts on the supply it contains, 
are the application of farm-yard manures and com- 
mercial fertilizers. 

335. Farm- Yard Manure consists of the excrements 
of the animals fed upon the farm, mixed with the 
straw used for litter, and other waste products of the 
farm. 

336. Commercial Fertilizers consist of various im- 
ported and manufactured articles with the refuse from 
slaughter houses, etc., worked up into a condensed 
form ready for immediate application. 

§ 4. Far 711- Yard Manure. 

337. Composition. — This varies greatly, depending 
on the kind and amount of litter used, the chafacter 
of the animals producing it, the food used, the length 
of time the manure has been kept, and the treatment 
it has received. 

338. Water forms the greater part. The remainder 
consists of carbonaceous matter ^fith a small amount 



FERTILIZERS. 155 

of nitrogenous substances and mineral salts. The fol- 
lowing table gives the composition of one ton of av- 
erage fresh farm-yard manure. 

Water 1,420 lbs. 

Nitrogen 9 lbs. 

Phosphoric acid 4.2 lbs. 

Potash 10.4 lbs. 

Carbonaceous matter, lime, sand, etc., 556.4 lbs. 

Total 2,000 lbs. 

ThijS represents an average sample of fresh manure. 
It will be seen that one ton contains only 23.6 lbs., of 
valuable plant food. Farm-yard manure from ani- 
mals fed on rich food may contain a much larger 
amount. 

339. Fermentation of Manure. — When fresh manure 
is allowed to remain in a heap, decomposition soon 
commences. The carbon combines with oxygen from 
the air, producing carbonic dioxide which is given oif. 
The nitrogen combines with hydrogen of the water 
forming ammonia. If the manure has become dry, 
this ammonia combines with the carbonic dioxide 
forming carbonate of ammonia (112), which escapes 
in vapor. If the heap has been kept moist, it com- 
bines with the organic acids formed by the decompo- 
sition of carbohydrates, producing soluble but not vo- 
latile salts. 

340. Considerable heat is produced during this 
process, which drives off much of the water in the 
manure. By fermentation of the manure, the amount 
of water and carbon in the heap is decreased, while 
the amount of nitrogen and mineral salts (if the pro- 
cess has been properly conducted,) remains un- 
changed. The manure, therefore, contains a larger 
proportion of these substances than before fermenta- 
tion, and more of the nitrogen is in an available form. 



156 SCIENCE IN FARMING. 

341. Manure Fermented in a Heap in Open Yard. — 

The following table shows the weight of a ton of ma- 
nure fermented in a heap in an open yard, and the 
amount of nitrogen contained in the heap at different 
dates : 

T.L^^r Nitrogen. 

November 3rd -2,000 lbs. 12.9 lbs. 

April 30th 1,428 lbs. 12.8 lbs. 

August 23rd... 1,405 lbs. 9.3 lbs. 

November 15th 1,391 lbs. 9.2 lbs. 

The manure used in this experiment contained con- 
siderably more nitrogen than that of which the analy- 
sis was given in paragraph 338. It will be noticed 
that during the first six months the weight of the ma- 
nure was reduced nearly 29 per cent, while the loss of 
nitrogen was immaterial. A ton of the manure ana- 
lyzed April 30th would have contained 20.2 lbs. of ni- 
trogen. During the next 6 months the decrease of 
weight was very small, but the loss of nitrogen was 
quite serious. A ton of the manure on November 
15th would only contain about 13 lbs. of nitrogen. By 
fermenting for six months in winter the weight of 
manure that would have to be handled to obtain a 
given amount of nitrogen was decreased, but by fer- 
menting six months longer nitrogen was wasted 
and the amount of manure required to contain a given 
weight of it was as great as at first. 

342. Manure Fermented Under Shed. — The follow- 
ing table shows the result of an experiment in fer- 
menting manure under a shed : 

^Al'Zt Nitrogen. 

November 3rd 2,000 lbs. 12.9 lbs. 

April 30th. 992 lbs. 10.2 lbs. 

August 23rd 800 lbs. 10.2 lbs. 

November 15th 758 lbs, 11,4 lbs, 



FEEDIN(J. l5t 

In this case the manure lost more than half its 
weight in the first 6 months, but it also lost 2.7 lbs. 
nitrogen per ton. This was probably due to the heap 
having been allowed to become too dry. During the 
next four months the heap lost in weight but not in 
nitrogen. On August 23rd the heap contained nitro- 
gen at the rate of 25.5 lbs. per ton. It will be noticed 
that the last date shows an actual increase in nitrogen. 
This must have been due to error in the analysis, un- 
less sufficient free nitrogen was oxidized in the heap 
to cause the increase. We have not sufficient facts at 
present to warrant this last supposition. 

343. Manure Spread in Barn- Yard. — The following 
table gives the result of an experiment with manure 
left spread in an open barn-yard : 

TotelWeight Nitrogen, 

or Manure. *= 

November 3rd 2,000 lbs. 12.9 lbs. 

April 30th 1,730 lbs. 9.2 lbs. 

August 23rd 1,226 lbs. 5 lbs. 

November 15tli 1,150 lbs. 4.5 lbs. 

In this case nitrogen was constantly lost, so that at 
the end of the year but little over one-third remained. 
The loss of nitrogen was in greater proportion than 
the loss of weight, so that the manure at the close of 
the experiment contained a smaller proportion of ni- 
trogen than at its commencement. 

344. Leaching. — When manure is exposed so that 
the rain which falls upon it leaches through, great 
loss of its most soluble, and therefore most valuable 
constituents is incurred. A heaj) of ordinary manure 
containing a ton of dry substance contains only 31 
lbs. of nitrogen and 35 lbs. potash, while sufficient of 
the dark colored drainage from the manure heap to 
contain one ton of drv substance would contain about 



158 SCIENCE IN FARMING. 

166 lbs. nitrogen and 554 lbs. potash. The nitrogen 
in the drainage is also entirely soluble, and hence 
much more valuable than that which remains. 

345. Evaporation of Ammonia. — We have seen (339) 
that the evaporation of ammonia may be prevented 
by keeping the heap sufficiently moist to insure the 
production of organic acids. It can also be prevented 
by the addition of gypsum or land plaster (109). 
Sulphuric acid diluted with water and sprinkled over 
the manure heap also prevents this waste by the for- 
mation of sulphate of ammonia, but it is neither as 
cheap nor as convenient as land plaster. 

346. Care of Manure. — From the facts already given 
the following practical applications may be made : 

By the fermentation of manure it loses carbon and 
water, causing considerable loss of weight and bulk, 
but if the fermentation is properly conducted there 
will be little or no loss of valuable constituents. 

If the manure while fermenting is allowed to be- 
come dry, serious loss of nitrogen will ensue. 

If so much water is allowed to fall on the manure 
that it leaches through and escapes by drainage, great 
loss of all the valuable constituents will result, and 
the exhaustion may be so complete that what re- 
mains will not be worth hauling to the field. 

By the use of gypsum loss of nitrogen by evapora- 
tion can be avoided. 

347. — Concentration. — It costs as much to haul and 
spread a ton of poor manure as a ton of the best ; con- 
sequently there is economy in having manure as con- 
centrated as possible. If a farmer has two heaps of 
manure, one weighing five tons and containing plant 
food worth $2.50, and another weighing only one ton 
but containg the same amount of plant food — and if 



FEEDINa. 159 

the cost of hauling and spreading is 50 cents per ton, 

the net value of the two heaps will be as follows : 

Five-ton heap coiitaiiiiiig i^lant food worth $2 50 

Less cost of hauling and spreading at 50 cents a ton 2 50 

Net value of 5 tons $0 00 

One-ton heap containing plant food worth $2 50 

Less cost of hauling and spreading at 50 cents a ton 50 

Net value of 1 ton $2 00 

§ 5. Jfaniirefrom Dlf event Animals. 

348. There is quite a difference in the manure pro- 
duced by different animals. The following table gives 
the average amount of water, nitrogen, phosphoric 
acid and potash in a ton of the fresh manure from 
different stock, the manure including solid and liquid 
excrements mixed with litter : 

Water. Nitrogen, "^^^^jf^^^"^^ Potash. 

Horse 1,426 lbs. 11.6 lbs. 5.6 lbs. 10.6 lbs. 

Cattle 1,550 lbs. 6.8 lbs. 3.2 lbs. 8 lbs. 

^heep 1,292 lbs. 16.6 lbs. 4.6 lbs. 13.4 lbs. 

Swine 1,448 lbs. 9 lbs. 3.8 lbs. 12 lbs. 

Poultry*.. . 1,120 lbs. 32.6 lbs. 30.8 lbs. 17 lbs. 

The manure from cattle and swine contains much 
more water than that of the horse and sheep, and con- 
sequently ferments less rapidly. In popular language, 
the one is said to be cold and the other warm. To se- 
cure the best results in fermenting manure, it is well, 
when possible, to have the manure of all the different 
animals mixed in one heap. This gives a composi- 
tion that causes fermentation to progress favorably. 

349. Solid and Liquid Manure. — There is a great dif- 
ference in the composition of the solid and liquid ex 
crement of animals. The former contains the greater 
part of the phosphoric acid ; the latter usually con- 

*Fresh, but without litter. 



160 SCtEifCt: IN FARMING. 

tains more of the nitrogen and potash. The manurial 
constituents in the solid excrement are mostly insolu- 
ble ; those in the urine are entirely soluble. 

The following table gives the amount of plant food 
contained in one ton of the fresh solid and liquid ex- 
crement of different animals : 

^ Nitrogen. ^^^"eM?"" ^^*^«^- 

Horse, solid excrement. . . 8.8 lbs. 7 lbs. 7 lbs. 

" Urine 31 lbs 30 lbs. 

Cattle, solid excrement. . . 5.8 lbs. 3.4 lbs. 2 lbs. 

'' Urine 11.6 lbs 9.8 lbs. 

Sheep, solid excrement. . . 11 lbs. 6.2 lbs. 3 lbs. 

Urine 39 lbs. .2 lbs. 45.2 lbs. 

Swine, solid excrement. . . 12 lbs. 8.2 lbs. 5.2 lbs. 

" Urine 8.6 lbs. 1.4 lbs. 16.6 lbs. 

The respective values of the different manures will 
be considered in a later portion of the chapter. 

The composition of manure varies with the consti- 
tution of the animal and its food. Analyses can there- 
fore give averages only. 

§ 6. delation of Food to Manure. 

350. The plant food in the manure must come from 
that contained in the food supplied to the animal. In 
the animal body a portion of the carbonaceous matter 
is burned up, and the product thrown off by the lungs 
(207), but nitrogen, phosphoric acid and potash are 
not disposed of in this manner. All of these sub- 
stances except what is used by the animal in the pro- 
duction of milk or increase, will be found in the ma- 
nure. 

351. If an ox is given food containing 100 lbs. dry 
substance, he will produce manure containing about 
36^ lbs. dry substance, and in this manure will be the 
greater part of the nitrogen, phosphoric acid and pot- 
ash that was contained in the food supplied. As the 



FEEDING. 161 

quantity of dry substance in the manure is much 
less than that in the food from which it was pro- 
duced, while the quantity of plant food is nearly 
the same, it follows that the dry substance in the ma- 
nure will contain a larger proportion of plant food 
than is contained in the dry substance of the food. 
The amount of plant food in the manure, however, 
cannot be greater than that contained in the food 
from which it was produced. 

352. Cause of Difference in Manure. — If a ton of 
corn is fed to an ox, and another ton to a sheep,* and 
all the manure collected, there will be exactly the 
same amount of plant food in the manure produced 
by each animal while feeding on the ton of corn-; but 
as the ox will have produced the larger quantity^ his 
manure will contain the smaller proportion of plant 
food. 

353. The difference, therefore, in the value of ma- 
nure produced by different animals is due to the fact 
that some remove more of the carbonaceous matter 
from the food supplied, and leave the manure propor- 
ti-onally richer. But no animal can furnish in the ma- 
nure any more i^lant food than is contained in the 
food it receives. 

Manure produced by animals fed on poor food will 
therefore be poor, while that produced by those fed 
on rich food will be rich. A ton of clover hay con- 
tains four times as much nitrogen as a ton of wheat 
straw ; therefore, other things being equal, the ma- 
nure made by feeding a ton of clover hay will con- 
tain four times as much nitrogen as that made by 
feeding a ton of wheat straw. 

*In this example it is supposed that neither ani7nal is in- 
creasing in weight. 
11 



162 SCIENCE IN FARMING. 

354. Proportion of Manure to Food. — When an ani- 
mal is neither increasing in weight nor giving milk, 
the manure produced will contain exactly the same 
amount of plant food that was contained in the food 
consumed."^ 

This is evident from the fact that the solid excre- 
ment contains all the nitrogen, phosphoric acid and 
potash of the undigested portion of the food ; and all 
of these substances contained in the digested portion, 
except what is used in the production of milk, stored 
up in increase of weight, and used for the repairs of 
the waste, is carried off in the urine. If the animal 
is neither growing nor giving milk, the urine will con- 
tain all these constituents except the amount used 
in repairing waste. The wasted substance is taken up 
by the blood and removed by the kidneys, and ex- 
actly balances the amount used in repair. 

355. When the animal is giving milk a portion of 
the nitrogen and phosphoric acid will be removed in 
the milk, and the manure produced will not usually 
contain more than from 50 to 75 per cent of the 
amount of these substances supplied in the food. 

356. When an animal is growing rapidly a consid- 
erable portion of the nitrogen and phosphoric acid 
contained in the food is used in the production of 
bone and muscle, and the manure contains a propor- 
tionally smaller amount of these substances than the 
food. 

357. The fattening animal takes comparatively 
little valuable material from the food, as the greater 

*This, of course, includes all the manure both solid and liquid. 
In the manner in which manure is often saved, or rather wasted, 
it would contain but a small portion of the plant food furnished 
the animals. 



FEEDING. 163 

part of the increase is fat, which contains no plant 
food. The following table shows the proportion of 
the nitrogen supplied in the food, that is stored up in 
increase, the proportion voided in the solid and liquid 
excrement, and in both, in fattening oxen, sheep and 

pigs : 

Oxen. Sheej). Pigs. 
Per cent nitrogen stored in increase . . . 3.9 4.3 14.7 
Per cent nitrogen voided in solid excre- 
ment 22.6 16.7 21 

Per cent nitrogen voided in urine 73.5 79 64.3 

Per cent nitrogen voided in total excre- 
ment 96.1 95.7 85.3 

With the fattening ox and sheep the manure con- 
tained about 96 per cent of the nitrogen supplied in 
the food. As the pig uses a larger proportion of the 
food he receives in production of increase, and less 
for heat and energy, the per cent of nitrogen supplied 
that goes into the manure is less than with either of 
the other animals. 

358. Of the phosphoric acid and potash contained 
in the food of a fattening animal, from 95 to 100 per 
cent will be found m the manure. 

359. The proportion of nitrogen received in food 
that is voided in solid and liquid excrement will vary 
with the kind of food supplied, and the table just given 
will therefore only be correct in this respect when 
the diet is the same as that on which the table was 
calculated. As the manurial ingredients in the di- 
gested portion of the food are voided in the liquid ex- 
crement and that in the unaigested portion in the 
solid, the more digestible the food the larger pro- 
portion of manurial ingredients will be contained in 
the liquid excrement. Thus, we have seen that a ton 
of wheat straw contains 60 lbs. nitrogenous matter 
(230), but that only 12 lbs. of this is digestedi(239). 



164 SCIENCE IN FARMING. 

If an animal were fed on wheat straw alone, there- 
fore, the solid excrement would contain at least 80 
per cent of the total nitrogen voided. By the same 
tables it will be seen that of the nitrogenous matter 
in beans, 88 per cent is digested, and therefore when 
an animal is fed on beans, the greater part of the nitro- 
gen voided will be in the urine. 

360. As the plant food contained in the solid ex- 
crement is mostly insoluble, while that in the urine is 
soluble, a pound of nitrogen in urine is worth more 
than the same amount in the solid excrement, and 
therefore the more digestible the food the more valu- 
able will be the plant food in the manure produced. 

361. We obtain from the foregoing facts the fol- 
lowing rules : 

The proportion of plant food in the manure will 
depend principally on the proportion in which it is 
contained in the food supplied to the animal. 

The plant food in the manure will be more valu- 
able in proportion as the food supplied to the animal 
is more digestible. 

Manure produced from working or fattening ani- 
mals will contain from 90 to 95 per cent of the manu- 
rial constituents contained in the food. 

Manure made from milk cows and young, growing 
animals, will contain from 50 to 75 per cent of the ma- 
nurial constituents contained in the food. 

362. Animal Food as Manure. — At one time rape 
cake was largely used in England as manure, it being 
sown with the seed. In this country cotton seed meal 
has been used for the same purpose, and some experi- 
menters have tried bran as a manure. 

363. We have already seen that the greater part 
of all vegetable substances is carbonaceous matter. 



FEEDING. 165 

valuable as food for animals but not as food for plants. 
For example, a ton of bran contains 1,044 lbs. of di- 
gestible food for the animal (239), but it only contains 
138.2 lbs. manurial constituents (372). If this ton of 
bran is fed to fattening oxen, the manure, if all saved, 
would contain about 132 lbs. of manurial constituents, 
while the remainder of the food might produce an in- 
crease of weight in the oxen of 130 lbs. There would 
therefore be a gain of 130 lbs. of weight in the oxen 
to compensate for the loss of six pounds plant food. 
The plant food in the manure would also be in more 
available forms than in the bran, and the actual value 
of the 132 lbs. in the manure would probably be 
greater than that of the 138.2 lbs. in the bran.* 

364. Plow Under or Feed. — The same principle will 
in some cases determine the question whether it will 
pay better to plow under a green crop or feed it to 
stock and return the manure. If on an acre of land 
there is a crop of clover that will make two tons of 
hay, it will contain plant food worth $17.52. If the 
clover is plowed under, this is all the value that will 
be obtained. If it is cut and fed to fattening cattle 
and the manure carefully saved and returned, the 
loss of plant food will be only 88 cents. The ques- 
tion of profit and loss will therefore be on the one 
hand the value of clover as food ; on the other, the 
cost of cutting, curing and feeding the clover, and of 
saving, hauling and spreading the manure, and the 
88 cents' worth of plant food lost. 



*It must be remembered that all such calculations as these 
are based on the supposition that all the manure is saved. 
Where the liquid manure is allowed to escape and the solid 
portion wasted by leaching and evaporation, such calculations 
will be very wide of the truth. 



166 SCIENCE IN FARMING. 

Any farmer, therefore, who can determine these 

points, namely : 

The feeding value of the clover, 
The cost of cutting and curing, 
The cost of hauling and spreading manure. 

Can readily determine whether it will pay best to 

plow under a crop of clover or feed it and return the 

manure.* 

§ 7 Valuation of Manure. 

365. The determination of the comparative values 
of different makes of commercial manures can be ac- 
complished with reasonable accuracy, but the com- 
parative values of farm-yard manures can be deter- 
mined approximately only. They not only vary 
greatly in the amount of plant food contained, but the 
value of that plant food differs according to the form 
of combination in which it may exist. A pound of 
nitrogen contained in urine is available for the plant, 
and is as valuable as a pound of nitrogen in nitrate 
of soda, or sulphate of ammonia. But nitrogen con- 
tained in half-digested straw is but slowly available, 
and may remain in the soil unused for years. 

366. For convenience the experiment stations of 
this country have adopted certain figures to represent 
the market value of nitrogen, phosphoric acid and 
potash, t 

*We have seen (171) that clover when plowed under may by 
the production of humus, serve other useful purposes in the 
soil besides furnishing plant food. In all cases where more 
humus is needed to improve the condition of the soil, a new 
element enters into the calculation of the comparative profit of 
feeding or plowing under. In such cases it will doubtless often 
be more profitable to plow under until the improvement in the 
condition of the soil has been accomplished. 

tThe mistake is sometimes made of supposing that these 
figures represent the value that these substances will be to the 



I^EEDINa. 167 

367. The valuations adopted by the Ohio State 
Board are : 

Kind of Plant Food. Price per lb. 

Ammonia 18 cts. 

Which is equal to nitrogen 21.86 cts. 

Phosphoric acid in soluble compounds 12 cts. 

Phosphoric acid in compounds insoluble in wa- 
ter but available as plant food 10 cts. 

Phosphoric acid in insoluble compounds which 
have to undergo decomposition in the soil be- 
fore they can be used by the plant 5 cts. 

Potash in soluble compounds 6 cts. 

The phosphoric acid in soluble compounds is called 

in the official analyses " soluble phosphoric acid." It 
is principally in the form of monocalcic phosphate 
(110). The phosphoric acid in compounds insoluble in 
water, but which can be used as food by plants, is 
called " reverted ;" it is principally contained in bi- 
calcic phosphate (110). The phosphoric acid in in- 
soluble compounds is called " insoluble phosphoric 
acid," and is principally contained in tricalcic phos- 
phate. 

In the estimation of the value of manurial constit- 
uents in farm-yard manures, we shall adopt the fol- 
lowing standard : 

PLANT FOOD IN MIXED MANURES. 

Nitrogen 15 cents. 

Phosphoric acid 8 cents. 

Potash 5 cents. 

farmer when applied to his field. No general estimate of this 
value can be made, as it depends on soil, season and circum- 
stance. A hundred pounds of nitrogen applied to the soil 
mi^ht in some cases be worth to the farmer a dollar a pound, 
under other circumstances it might not l^e worth a dollar for 
the hundred pounds, or might even prove a detriment. There- 
fore when the statement is made that nitrogen is worth 22 
cents a pound, the meaning is that it can usually be bought in 
the market for that price in forms that are immediately and en- 
tirely available for plant food. Whether the nitrogen will be 
worth that amount to the farmer in every particular case must 
be determined by other considerations. 



168 SCIENCE m FARMING. 

PLANT FOOD IN SOLID EXCREMENT. 

Nitrogen 10 cents. 

Phosphoric acid , 6 cents. 

Potash 4 cents, 

PLANT FOOD IN URINE. 

Nitrogen 22 cents. 

Phosphoric acid ■ 12 cents. 

Potash 6 cents. 

PLANT FOOD IN FOODS. 

Nitrogen 15 cents. 

Phosphoric acid 8 cents. 

Potash 5 cents. 

368. Plant food in ordinary barn-yard manure is 
not worth as much as in nitrate of soda, sulphate of 
ammonia, superphosphate, etc., on account of being 
in forms that are less readily available to the plant. 
The constituents of urine being already in solution 
are of the highest value. The determination of the 
value of the manurial constituents in foods is a mat- 
ter of difficulty and one in which strict accuracy is 
impossible. The more digestible the food the more 
valuable are the manurial constituents it contains. 
Therefore in the table in paragraph 372 the estimated 
value of poor and indigestible foods is liable to be too 
high, while that of rich foods is probably below the 
truth. 

369 . Tables of Values of Farm- Yard Manures. — These 
tables represent approximately what the same quan- 
tities of nitrogen, phosphoric acid and potash in 
equally available forms would cost in commercial 
fertilizers: 

VALUE OF 1 TON FRESH FARM- YARD MANURE.* 

Nitrogen 9 lbs, @ 15 cents $1 35 

Phosphoric acid 4.2 lbs. @ 8 cents 34 

Potash 10.4 lbs. @ 5 cents 52 

Total value 1 ton $2 21 

*As usually found in the barn-yard ; composed of the mixed 
excrements of diflerent stock with the straw used as litter. 



FEEDING. 169 

WELL ROTTED FARM-YARD MANURE.* 

Nitrogen 11.6 lbs. @ 15 centst $1 74 

Phosphoric acid 6 lbs. @ 8 cents 48 

Potash 10 lbs. @ 5 cents 50 

Total value 1 ton $2 72 

FRESH HEN MANURE. t 

Nitrogen 32.6 lbs. @ 15 cents $4 89 

Phosphoric acid 30.8 lbs. @ 8 cents 2 46 

Potash 17 lbs. @ Scents 85 

Total value of 1 ton %^ 20 

AIR DRIED HEN MANURE. 

Nitrogen 65.2 lbs. @ 15 cents $9 78 

Phosphoric acid 61.6 lbs. @ 8 cents 4 93 

Potash 34 lbs. @ 5 cents 1 70 

Total value 1 ton ^^16 41 

FRESH SOLID EXCREMENT, HORSES. 

Nitrogen 8.8 lbs. @ 10 cents $ 88 

Phosphoric acid 3.4 lbs. @ 6 cents 20 

Potash 7 lbs. @ 4 cents 28 

Total value of 1 ton H 36 

FRESH SOLID EXCREMENT, CATTLE. 

Nitrogen 5.8 lbs. @ 10 cents $ 58 

Phosphoric acid 3.4 lbs. @ 6 cents 20 

Potash 2 lbs. @ 4 cents 08 

Total value of one ton $Q ^6 

FRESH SOLID EXCREMENT, SHEEP. 

Nitrogen 11 lbs. @ 10 cents $110 

Phosphoric acid 6.2 lbs. @ 6 cents 37 

Potash 3 lbs. @ 4 cents 12 

Total value of one ton $1 ^^ 

*The manure from which this analysis was made must 
have been rotted in an open yard, and exposed to waste both by 
leaching and evaporation, otherwise it would show a higher 
value in proportion to the fresh. It is however, probably a 
fair representation of the rotted manure that will be found m 
most barn-yards. 

tif the nitrogen in the fresh manure is worth 15 cents a pound 
that in the rotted manure (if fermentation is properly con- 
ducted) is worth more. 

iManurial constituents in hen manure are probably more 
soluble and therefore really worth more per pound than m the 
mixed farm-yard manure. 



110 sciENOfi enTfarmin^. 

FRESH SOLID EXCREMENT, SWINE. 

Nitrogen 12 lbs. @ 10 cents $120 

Phosphoric acid 8.2 lbs. @ 6 cents 49 

Potash 2.6 lbs. @ 4 cents 10 

Total value of one ton $1 79 

FRESH URINE, HORSES. 

Nitrogen 31 lbs. @ 22 cents $6 82 

Potash...' 30 lbs. @ 6 cents 1 80 

Total value of one ton $8 62 

FRESH URINE, CATTLE. 

Nitrogen 11.6 lbs. @ 22 cents $2 55 

Potash 9.8 lbs. @ 6 cents 59 

Total value of one ton $3 14 

FRESH URINE, SHEEP. 

Nitrogen 39 lbs. @ 22 cents $8 58 

Phosphoric acid 0.2 lbs. @ 12 cents 02 

Potash 45.2 lbs. @ 6 cents 2 71 

Total value of one ton $ 11 31 

FRESH URINE, SWINE. 

Nitrogen 8.6 lbs. @ 22 cents $189 

Phosphoric acid 1.4 lbs. @ 12 cents 17 

Potash 16.6 lbs. @ 6 cents 1 00 

Total value of one ton $3 06 

370. These tables should have careful study. 
Farmers who allow their liquid manure to drain away 
but carefully preserve the solid may be surprised to 
learn that while a ton of the solid excrement of a 
horse is worth only $1.36, a ton of urine is worth $8.62. 
It is true that these figures represent only the com- 
mercial value of these substances, and not their value 
when applied to the soil, but the proportion will 
be correct, even if the actual value differs. Thus if a 
ton of solid horse manure under certain circumstances 
is worth to the farmer one-half more than the figures 
given, under the same circumstances a ton of the 
urine will also be worth one-half more than the 
figures given. If under certain circumstances the 
ton of urine is not worth $8.62, then, under the same 



FEEDING. lYl 

circumstances a ton of solid will not be worth $1.36.* 
Urine being rich in nitrogen in a form that is im- 
mediately available, renders it sj)ecially valuable as a 
top dressing for crops requiring this substance. 

371. Valuation of Foods as Manures. — The knowledge 
of the manurial constituents of foods and their value, 
is of considerable practical imi)ortance, as it has 
much to do with the profits of feeding and the choice 
of foods. Two foods may have equal feeding value 
and cost about the same, but the manure produced 
from one be worth more than that produced from the 
other. By knowing the feeding value of each food 
and the value of the manure produced from it, a 
farmer can often make a calculation whether it will 
pay to sell some article of food and buy another. 

The question is often asked whether it will pay to 
sell straw, the opinion being held by many that a 
farmer who sells straw will im^Doverish his farm. B}^ 
reference to the following table it will be seen that 
the plant food in a ton of straw is worth $2.44, while 
that in a ton of bran is worth $13.25. Then if a farmer 
can sell straw for $2.44 i3er ton and buy bran at $13.25 
a ton, there would be no loss as far as elements of 
fertility are concerned. There would be in fact a 
slight gain, as the plant food in the manure produced 
by feeding the bran w^ould be in a more available 
condition than that in the straw, f 

372. Sir J. B. Lawes, of England, many years ago 
prepared a table giving the value in money of the 

*An exception to this rule may arise from difference in the 
cliaracter of the two manures. L^rine is ricli in nitrogen and 
potash, but contains no phosphoric acid. When this latter 
substance is the one needed by the soil, the solid manure will 
have the greater proportional value. 

fin this we have considered only the value of the plant food 



172 



SCIENCE IN FARMING. 



manurial constituents in different foods. Since its 
publication this table has been the standard in this 
country as well as England. The following table is 
calculated on the basis of valuation given in para- 
graph 367, and differs slightly from that of Lawes : 

AMOUNT AND VALUE OF MANURIAL CONSTITUENTS CONTAINED IN 
ONE TON OF DIFFERENT FOODS. 

Name of Food ^.?^^^^^ ^7^4^ ^^'?r P«""^« Value. 
-Nitrogen phone acid Potash 

Linseed cake 90.0 39.2 29.4 $18 10 

Cotton cake, decorticat- 
ed 132.0 02.4 30.0 26 29 

Cotton cake, undecorti- 

cated 78.0 45.8 40.2 .17 37 

Beans 82.0 23.2 24.0 15 36 

Peas 72.0 17.6 19.6 13 18 

Bran 44.0 64.6 29.6 13 25 

Oats 41.2 12.4 9.0 7 62 

Barley 34.0 14.6 9.8 6 76 

Indian corn 33.2 12.2 7.2 6 32 

HAY AND STRAW. 

Clover hav 39.4 11.2 39.0 8 76 

Meadow hay 31.0 7.6 33.6 6 94 

Wheat straw 9.6 5.2 11.6 2 44 

Barley straw 10.0 4.0 19.4 2 79 

Oat straw 10.0 5.0 20.8 2 94 

Pea straw, cut in bloom 45.8 13.6 46.4 10 28 

Pea straw, ripe 20.8 7.0 20.2 4 69 

Cornstalks 9.6 10.6 19.2 3 25 

GREEN FODDER. 

Grass 10.8 3.0 9.2 2 32 

Red clover 10.2 2.8 8.8 3 37 

Peas 10.2 3.0 10.2 2 50 

Oats 7.4 3.4 15.0 2 73 

Rye 10.6 4.8 12.6 2 60 

Corn 3.8 2.6 8.6 1 21 

Hungarian 20.0 2.5 17.0 4 05 

Sorgum 8.0 1.6 7.2 169 

ROOTS. 

Potatos 6.8 3.6 11.2 1 87 

Mangels 3.8 1.4 7.8 1 07 

Carrots 3.2 2.0 6.4 96 

Turnips 3.6 1.2 5.8 5 77 

373. From this table and the rules laid down in 



contained in the straw. When straw is used as an absorbent, 



* FEEDING. 173 

paragraph 361, a farmer can calculate the value of 
the manure^produced by feeding a given quantity of 
any kind of food to any class of stock. 

Thus, a ton of hay with half a ton of corn meal, and 
500 lbs. mangels contains plant food worth $10.62. If 
this were fed to fattening oxen, 95 per cent of the 
plant food would be contained in the manure produced, 
which would therefore be worth $10.09. A ton of corn 
meal fed to fattening cattle would produce manure 
worth $6.00. Fed to fattening pigs the manure pro- 
duced would be worth $5.37. Fed to milk cows the 
manure produced would not be worth more than $4.74.* 

§ 8. Commercial Fertilizers. 

374. The use of commercial fertilizers has greatly 
increased during the past few years. Their composi- 
tion is often very uncertain, and in localities where 
there is no efficient fertilizer law in force, they should 
be purchased with caution. In Ohio and some other 
states the manufacturer is required to print the 
analysis on every package, and a heavy penalty is im- 
posed if the composition does not agree with the 
printed analysis. 

375. Bone Dust. — This is bones reduced to a powder, 
and when pure the composition is the same as bones. 
One ton contains : 

Nitrogen 76 lbs. 

Phosphoric acid 364 lbs. 

The phosphoric acid is in the form of tricalcic phos- 

and prevents the waste of liquid manure, it has a practical 
value greatly in excess of the plant food it contains. Thus, if 
a farmer sells a ton of straw, and in consequence of the lack of 
sufficient absorbents allows a ton of horse urine to be wasted, 
the total loss, direct and indirect, would be $11.06. 

*A11 these calculations are made on the supposition that 
none of the manure produced is wasted. 



174 SCIENCE m FARMING. ' 

phate, and is therefore not available as plant food 
until it has undergone decomposition in the soil. 
Grinding the bones by increasing the amount of sur- 
face exposed (164) facilitates this decomposition, but 
the action is comparatively slow, and the effect of a 
dressing of bone dust is spread over several years. On 
account of its insolubility, bone dust may sometimes 
be used with advantage on soils that possess but 
little power of retaining fertilizers. 

376. Guano is the excrement of sea fowls, that has 
in some places been accumulating for ages. It is 
l)rincipally obtained from the islands of the Pacific. 
The valuable constituents are phosphoric acid and 
nitrogen. That which comes from countries where no 
rain falls, contains a large amount of nitrogen, some- 
times as much as 240 lbs. to the ton. Where it has 
been exposed to rain the nitrogenous matter has been 
mostly washed out, and little but the phosphoric acid 
remains. Phosphatic guanos are often converted into 
superphosphates by treatment with sulphuric acid. 

Owing to the uncertainty of its composition no 
analysis of guano can be given that would apply to 
more than one sami)le. It should always be bought 
on the analysis of the particular brand. 

377. Rock Phosphate . — Large deposits tricalcic phos- 
phate are found in some places, (110) and are called 
''rock i^hosphate." These deposits are the remains of 
marine animals. The organic matter has wasted, 
and the calcic phosphate of the bones become com- 
pacted into a mass like rock. This is ground to a 
powder, as fine as flour, and in this condition used 
as a fertilizer. It is most valuable on soils rich in 
humus, as the organic acids they contain assist in its 
decomposition and solution. It is also rendered more 



FEEDING. 175 

soluble by composting with barn-yard manure. It 
contains no plant food of value, except j)hosphoric 
acid. Rock phosphate is often converted into super- 
phosphate by treatment with sulphuric acid. 

378. Salts Containing Nitrogen. — Those in common 
use as fertilizers are the sulphate and chloride of am- 
monia, and nitrate of soda, (108, 109 and 113). They 
are valuable only for the nitrogen they contain. Be- 
ing entirely soluble they act very rapidly and will 
give nearly all their effect the same year they are 
applied. Lawes and Gilbert found that 45 to 50 per 
cent of the nitrogen in these salts was recovered in 
the increased crop the first year, when applied to wheat 
and barley ; but that the following year showed very 
little effect from their application. 

Owing to their solubility these salts are very liable 
to be washed out in the drainage water, if applied at 
a season when the crop cannot make immediate use 
of them. They are best applied as a top dressing in 
the spring. 

379. Superphosphate. — The composition of super- 
phosphate and the principles of its manufacture have 
already been given (111). Commercial superphos- 
phate is a mixture of monocalcic phosphate with 
gypsum. It also usually contains some free phos- 
phoric acid, and bicalcic, and tricalcic phosphate. 
When prepared from bones it also contains a consid- 
erable per cent of nitrogen. To increase the amount 
of nitrogen, blood, shoddy, leather waste, and the 
refuse of slaughter houses are frequently added. The 
character and composition of any particular brand can 
only be determined by analysis. 

Many of the commercial superphosphates contain a 
large per cent of nitrogen and potash, while others. 



176 SCIENCE IN FARMING. 

especially those made from rock phosphate contain 
only phosphoric acid. 

The advantage of converting bones and rock phos- 
phate into superphosphate is due to the greater solu- 
bility of the monocalcic phosphate. No plant food is 
added by the process. 

380. Manufacture of Superphosphate. — The princi- 
ples of the manufacture have already been given 
(111). In practice it will rarely prove profitable for 
the farmer to manufacture his own. The proportions 
would be, theoretically : 

Bones 100 lbs. 

Sulphuric acid 35 lbs. 

Water 13 lbs. 

Which would produce 148 lbs. dry superphosphate. 
In practice, several times as much water would be 
needed to make it possible to mix the mass. The 
bones should be put in a wooden vessel, and the water 
poured over them. The acid should then be added, a 
little at a time. If all the acid is added at once the 
mixture will be so strong that it will be liable to de- 
stroy the wooden vessel. Therefore time, between 
each addition of acid, must be allowed for it to com- 
bine with the bones. The decom^sition of whole 
bones by sulphuric acid is a slow and tedious process. 

§ 9. Adaptation of Manures to Crops. 

381. Different crops require very different supplies 
of food. The table in paragraph 331 shows the 
amount of different manurial ingredients removed by 
different crops, but the proper manure for each crop 
cannot be determined by such a table. Thus, it will 
be seen that a crop of clover removes from the soil 
more than twice as much nitrogen as a crop of wheat, 
and yet wheat specially needs nitrogenous manures, 



ffiRTILIZERS. 177 

while clover does not. The reason of this is some 

crops have greater ability to obtain certain substances 
from the soil than others. 

It was formerly taught that all the constituents of 
plant food contained in a crop must be added in the 
manure. This is no longer considered necessary. If 
each crop is manured with the particular substance 
most needed for its successful growth, and a judicious 
system of rotation followed, the best results will be ob- 
tained in proportion to the manures used, and no un- 
due strain will be made on the capabilities of the soil. 

382. Cereal Crops. — These crops, in general, are spe- 
cially benefitted by nitrogenous manures. In the ex- 
periments at Hothamsted it was found that from forty 
to eighty pounds of available nitrogen to the acre se- 
cured a maximum crop. Potash is usually of little 
value. Phpsphoric acid when used alone seldom pro- 
duces much effect, but is beneficial in connection 
with nitrogen.* 

383. Indian Corn.— No satisfactory experiments 
have yet been made to determine the best manures 

. for corn. Phosphoric acid appears to be beneficial in 
many cases, and when combined with nitrogen, good 
results are usually obtained. Land plaster is a fa- 
vorite manure for this crop. 

384. Grass — Requires all the elements of plant 
food, and well rotted stable manure applied as a top 

*It is the opinion in many parts of this country that phos- 
phoric acid is the manure specially needed for wheat. This 
opinion is probably due to the fact that throughout the West 
the superphosphates used have been mostly prepared from 
bones, and contain nitrogen, often in considerable quantity. 
The general result of experiments with purely phosphatic ma- 
nures are that, unless combined with nitrogen, they are seldom 
of much value for cereals. 
12 



ItB SCiENCli: IN I'ARMma. 

dressing to old meadows or pastures supplies this 
need. Bone-dust is also especially valuable for this 
crop, and can be sown broadcast. 

385. Clover. — Although clover contains a larger 
amount of nitrogen than almost any other crop grown 
on the farm, it does not seem to need nitrogenous 
manures. Potash and lime are the most valuable 
manures, the lime being best applied in the form of 
land plaster. 

386. Turnips — Require nitrogen and phosphoric 
acid. They seem to have little ability to appropriate 
the phosphoric acid existing in the soil in insoluble 
combinations ; hence fresh applications of superphos- 
phate in connection with farm-yard manure have a 
remarkable eft'ect. In England superphosphate is 
chiefly used for turnips, which are one of the most im- 
portant crops grown there. Nitrogen without phos- 
phoric acid will not secure a full crop. 

387. Mangels — Obtain much less benefit than tur- 
nips from phosphoric acid, and require more nitrogen. 
Mixed farm-yard manure is suitable. 

388. Potatos — Are similar to turnips, giving best 
results from use of phosphoric acid and nitrogen. In 
soils deficient in potash this is an essential constit- 
uent in the fertilizer used ; but soils that have been 
manured with farm-yard manure usually contain 
sufficient potash. 

§ 10. Summary. * 

The problem of maintaining the fertility of the 
farm can only be satisfactorily solved by a considera- 
tion of all the principles taught in this chapter. 

The farmer who drains and cultivates, but fails to 
restore to his land, in a measure at least, the elements 



FERTILIZERS. 179 

of fertility that have been removed in the crops, will, 
sooner or later, reduce the amount of available plant 
food in his soil to such a degree that the production 
will be seriously decreased. 

The farmer who carefully saves all his manure and 
returns it to the soil, but pays no attention to drain- 
ing, and but little to cultivation, who allows weeds to 
grow and rob the plants, will probably complain that 
manuring does not pay — for no amount of manuring 
will secure good crops on soil that needs draining, or 
where the proper mechanical conditions are not pro- 
vided. 

The farmer who builds his barns and stables on a 
side-hill, allows all the liquid manure to escape into a 
creek, and keeps the solid portion where the drip- 
pings from the roofs will fall upon and leach through 
it, will be very likely to reach the conclusion that 
manure is of little value and will not pay for hauling 
to the field. And his conclusion will probably be 
correct with' reference to the manure he uses. 

It has been shown (160) that when a judicious rota- 
tion is followed, a good proportion of the crops fed on 
the farm, and all the manure carefully saved and re- 
turned, that the drain upon the soil will be but small. 

It would seem, in fact, that under such circum- 
stances, there is no need, at least at present, for pro- 
curing plant food from sources away from the farm. 
The farmer is not required to make provision for con- 
tingencies that may arise from seven hundred to three 
thousand years hence. If he uses care and judgment, 
he may not only produce on his farm the material 
needed for maintaining the fertilitity of his soil, but, 
by rendering soluble the plant food it already contains, 
actually increase its fertility. It should be ever borne 



180 SCIENCE IN FARMINCJ. 

in mind that it is not alone the amount of plant food 
in the soil that determines its fertility, but also the 
forms of combination in which that plant food exists. 

Most soils contain a great amount of plant food, 
and hence treatment such as drainage, cultivation, 
lime, fallow, and green crops, which do not add plant 
food, but only change the condition of that already 
X3resent, are often successful in changing a compara- 
tively barren soil into a fertile one. And if, after fer- 
tility has thus been obtained, the greater part of the 
crops grown on such a soil are fed on the farm and 
the manure produced returned to the soil, the fertility 
may be long maintained without the addition of plant 
food from sources outside the farm. 

If, however, it is desirable to rapidly bring a poor 
soil to a condition of fertility, there can be no doubt 
of the value of commercial fertilizers, as these will 
enable the farmer to grow large crops with which to 
make much manure that can be brought back to 
the soil. 

When the farmer wishes to make the growing of 
grain, to be sold off the farm, his principle business, 
the use of imported fertilizers will sooner or later be- 
come a necessity. 

In many cases one of the most economical methods 
of obtaining plant food from outside sources, is to buy 
bran, linseed or cotton seed cake, etc., and feed it to 
stock, carefully saving the manure. 



INDEX. 

Numbers refer to Paragraphs, not to Pages. 



Acid, nitric 101 

'' exists in the air 138 

phosphoric ... 100 

silicic 103 

sulphuric 102 

" mixing with water 102 

Acids and alkalies distinguished . . 63 

Acids, definition of 62 

vegetable ] 24 

Agricultural plants * 166 

Adhesiveness of soils 154 

AflBnity 59 

Air. composition 133 

uniformity of 134 

dried in a stove room 141 

how warmed 52 

what the farmer gets from 143 

Albumin 127 

Albuminoid ratio 255-264 

error in caused by amides 256 

for fattening animals 297 

for milk 291 

for working animals ■ . 314 

for young animals 284 

of mixed diets 260-262 

to determine 257-258 

Albuminoids 126 

decrease in plants as seed forms 192 

effect of insufficient in food 21s 

high value in some cases 248 

how formed 187 

meet all needs of animals 210 

oxydized in circulation 207 

term how used 225 

used for repairing animal waste 213 

used in making new tissue 213 

value of as food 249 

Aftermath hay, analysis of 293 

Alkaloids 129 



*Will be found in foot note. 



Alumin um 93 

Amides 128 

cannot be changed to albumi- 
noids 226 

often classed as albuminoids . . 225 
proportion of in different food 240 

Ammonia, absorbed by soils . 153 

chloride 378 

composition 98 

contained in air 133 

cost of 98 

evaporation of, how prevented 345 

for house plants 98 

quantity of in air 142 

retained in soils 153 

source of in air 142 

sulphate .378 

uses in the household 98 

Ammonic carbonate 112 

chloride 113 

Amyloids 117 

Analysis of soils, value of 157 

Animal cannot use inorganic mat- 
ter 203 

composition of 198-202 

matter compared with vegetable 202 
Animals, the farmer's machine. 267-270 

Annual, process of forming seed 192 

Ash, amount in plant 180 

constituent of animals 200 

Assimilation 20."> 

Atoms, definition of 18 

Atomic theory 75 

weight 76 

' ' application of 79 

B 

Bacterium 163 

Bases, definition 62 

Bicalcic pliosphate 110 

Biennials 193 

Black lead, nature of 88 

Bone dust 375 



182 



SCIENCE IN FARMING. 



Bulbs, storehouse of food 194 

Burning butter 272-273 

C 

Calcareous soils, Low known 112 

Calcic carbonate , 112 

oxide 107 

Calcium 92 

Capillary attraction 150 

Carbohydrates 118 

do not exist in animals 199 

value of as food 249 

Carbon 88 

Carbonate of ammonia 112 

of lime 112 

Carbonates 112 

Carbonic dioxide, amount in air 99 

composition 99 

contained in spring water 99 

how produced 99 

in cellar or pit 136 

in hard water 99 

needed by plants 99 

Poisonous 99 

quantity of in air 139 

removed by lungs . . 207-208 

supplies carbon for plants 139 

taken up by roots of plants 186 

Carcass, proportion in increase. .311, 312 
" of live weight . . 313 

Casein 127 

Catalysis 122 

Cellulose 119 

Cereal crops, manure for 382 

Character of food, meaning of term* 238 

Charcoal, nature of 88 

Chemical combination 57 

force 59 

symbols 80 

Chemisim 59 

Chemistry, its nature 56 

of carbon compounds 114 

Chemistry, agricultural 11 

value of to farmers 10 

Chili saltpetre 108 

Chloride ammonia 113 

Chlorphyl 187 

Chlorine 87 

Clay, character of 170 

effect of lime on 170 

origin and composition 146 

soils, how improved 176 

Clouds, protect from frost 54 

Numbers refer to paragraphs, 



Clover, injured in curing 236 

manure for 385 

plow under or feed 364 

Cold, effect of 221, 223 

effect of in feeding 273 

Colostrum, analysis of 280 

Combining proportions 72 

Combustion 131 

Compounds, how described 82 

how represented 81 

proportion of elements in 96 

Conduction, difference in 42 

Copperas 109 

Corn, not a complete diet for pigs. . 309 
Crops, i-equire different manures . . . 381 

Crude iibre, meaning of 228 

D 

Dark soils, absorb warmth 152 

Decay 132 

Decimals, definition of 30 

Dew-point 140 

Dew, why none on cloudy nights — 140 

Dextrine 120 

Dextrose t 122 

Diamond, nature of 88 

Diffusion of gases 135 

Digestibility of food, affects its char- 
acter 238 

of food affected by mixing . . . 244-247 

" " " " maturity 243 

" " differs 237 

Digestion 204 

most perfect how secured 247 

Disinfectant, copperas 109 

Division, effect of 164 

Drainage, effect of 166-168 

warms the soil 50 

Drought, prevented by drainage . . . 168 
Dry soils, become warm quickly. . . . 152 

Dry substance, meaning of 179 

E 

Element, definition of 21 

Elements, list of agricultural 83 

Energy, animal, source of 211 

original source of 37 

Equivalents 78 

Eremacausis 132 

Excrement, solid, undigested food. . 208 

Excretion 208 

Exercise, effect of 221-223 

effect of in feeding 272 

* tWill be found in foot note. 

not to pages . 



INDEX. 



183 



Exhaustion, of soils IM 

ill rotation IW 

F 

Fallow, bare 326 

Farmer, ti manufacturer 

need of knowledge — 7 

may prove injurious 32() 

Fat, how digested 2(i4 

how produced in plants 1S7 

not changed into albumin 210 

produced from albuminoids 213 

production of 211 

rule for reducing to value in car- 
bohydrates 25(>-2r)2 

used for production of fat 2ir) 

value of as food 249 

Fats 12.-) 

Fattening animal, composition of 

increase 29") 

animals, variation in rate of in- 
crease 306 

experiments in 2'.»5-3()8 

Fertilizers, commercial 374-380 

definition 317 

Feeding, effects of cold in 273-275 

effect of exercise in 272 

general principles of 265-279 

objects to be attained in 265 

Ferric oxide, retains fertilizers 151 

Fertility of soil, affected by its fine- 
ness 164 

Fibrine 127 

Fixed oils 125 

Flesh formers, use of term 229 

Food, adaptation of 271 

best for young animals 280-284 

comparative value of 254 

composition affected by soil and 

season 235 

composition of 230-236 

consumed for heat and en- 
ergy 299, 303 

digestibility of 237-247 

disposition of 212-217 

for producing milk 285-294 

for fattening animals 295-298 

insufficient, effects of 218-220 

must contain all elements used 

by animal 210 

of what composed 224 

pounds of digestible constituents 
in ton 239 

Numbers refer to paragraphs 



Food required to make 1 pound 

increase 299-302 

surplus how disposed of 214 

table of composition 230 

undigested how disposed of 217 

used for production of heat and 

enei-gy 212 

uses of in animal body 209-211 

valuation, comparative 248-254 

valuation of manurial constitu- 
ents in 371-372 

value of not determined by anal- 
ysis 237 

Force, definition of 19 

Formula, chemical 82 . 

Free, meaning of term 70 

Fungi, how they feed * 187 

Gases 17-18 

Gelatin ;.. 127 

Germination, chemistry of 183 

general summary 195 

necessities of 184 

temperature required for 184 

Glucose 122 

how made 122 

Gluten 127 

Grass, manure for ... 384 

Green manuring 328 

Guano 376 

Gums 121 

Gypsum 109 

use in manure 109, 345 

H 

Hay, effects of methods of preparing 236 

composition affected by date of 

cutting 232 

Heat, absorption of 46 

animal, source of 211 

cannot be destroyed 37 

conduction of 41 

convection of 43 

excessive cause waste in feeding 275 

needed for melting ice 34 

needed to boil water 34 

origin of 38 

produced in freezing 36 

produced in slaking lime 35 

producers, use of term 229 

protection from 48 

radiation of 44 

*Will be found in foot note, 

, not to pages . 



184 



SCIENCE IN FARMING. 



Heat, same principle as energy. . . . 32-36 

specific 39 

transference of 40-46 

Horse, digestive power of 241 

Horsefall's experiments inj feeding 

cows 294 

How the plant grows 185-190 

Humus, power of retaining water. . 148 

to estimate quantity in soil 171 

origin of 146 

retains fertilizers I'll 

value of in soil 171 

Hydrogen 85 

I 

Indian corn, manure for .383 

Inulin 120 

Iron 94 

black oxide 94 

in soils, bow rendered harmless. 94 

red oxide 94 

when injurious in soils 94 

Isomerism 116 

Laevul ose 122 

Land plaster 109 

Leaves, effect of removal 189 

exhaustion in fall 189 

work of 187 

Lime, as a manure 327 

effect on ammonia 107 

on clay soils 170 

quick 107 

slacked 107 

Liquids 17-18 

Loam 147 

M 

Magnesium 92 

Manganese 95 

Mangels, manure for 387 

Manure, adaptation 381-388 

affected by digestibility of 

food 359-360 

amount produced from food 351 

animal food used for 362-363 

becomes rich by fermentation .. .340 

cause of difference in 354-355 

comes from food 350 

composition of drainage from. . . 344 

concentration of 347 

farm-yard, composition 37-338 

fermentation of 339 

fermented in open barn-yard 341 

fermented under shed 342 

Numbers refer to paragraphs, 



Manure, for cereal crops 382 

for clover 385 

for grass 384 

for Indian corn 383 

for mangels 387 

for potatos 388 

for turnips 386 

from animal giving milk MH 

from different animals. . 348-349 

from fattening animals 3,57 

from growing animals 356 

improve mechanical condition of 

soils 532 

leaching of 344 

left spread over the yard 343 

poor from poor food 353 

proportion of to food 354 

relation of food to 350-364 

rich from rich food 353 

rules for care of 346 

solid and liquid 849 

tables of value 369 

valuation of .365-373 

varies with food and constitu- 
tion of animals 349 

Manures, plant food required in ... 330 

Matter, can change its form 15 

cannot be created 15 

cannot be destroyed 16 

definition of 15 

forms in which it exists ... 17 

properties of 20 

Milk, analysis of 280, 310 

best food for 285-294 

food used in production 216 

key to proper food for young an- 
imals 280 

Molecular weight 77 

Musculine 127 

N 

Nature and cultivation 319 

Nitrate of soda 108, 378 

Nitrates 101, 108 

how saved in soil 156 

Nitrification 163 

Nitrogen 86 

amount brought down by rain. . 138 

lost in fermenting manure 339 

oxydized in soil * 329, 378 

proportion stored in increase . . . 357 
rendered.available by bare fallow 326 

*\Vill be found in foot note. 

not to pages . 



INDEX. 



185 



Nitrogen not used uncombined 

Nitrogenous substances 

Nutrition, animal 203- 

O 

Open fires 

Organic chemistry 

matter oxydized in soil 

substances, classes of 

substances, definition 

substances, of what composed . . 
Oxygen 

uses in air 

P 

Parasitic plants, food of * 

Pectose group of substances 

Per cent, definition of 

practical use of 

Percentage composition 

Perspiration protects from heat ... 
Pig, amount increase from food 299- 

clover for 

digestive powers of 

experiments in feeding 

the farmer's most profitable 

stock 

Phosphates 

preparation of 

rendered soluble in soil 

Phosphoric acid, insoluble 

proportion of in solid excrement 

reverted 

soluble 

Phosphorus 

Potatos, manure for 

Plants composition of 178- 

exhaustion with age 

in bed-rooms * 

prepare food for animals 

supplied with carbon by leaves . 
Plant food, amount of in soils 

available, an excess needed in 
the soil 

available, may be exhausted . 

condition of in the soil 

means for rendering available 326 

of what composed 

valuation 367 

Potash, caustic 

use of term in fertilizers 

Potassic Hydrate 

Potassium 



138 
117 

-208 

.51 
114 
162 
117 

71 
114 

84 
137 

187 

123 

27 

29 

28 

49 

-304 

283 

242 

806 

302 
110 
111 

162 
367 
358 
367 
367 
89 
388 
181 
192 
190 
203 
188 
160 

333 
332 
161 

-329 
185 
368 
104 
104 
104 
92 



*WiU be found In foot note. 



J^nmbers refer to paragraphs, 



K 

Respiration, of plants 190 

of animals 207 

Rock, liow reduced to soil. 14.5 

phosphate 377 

Roots, best use in feeding 279 

improve with maturity 233 

work of 186 

Rotation, exhaustion of soils in 160 

S 

Sacharose 122 

Sal ammoniac 113 

Saltpeter 108 

amount in water of the Nile. ... 156 

Salts, containing nitrogen 378 

definition of term 6.'> 

Sand 146 

absorbs water but slightly 149 

determination of character and 

amount 169 

retains fertilizer but little 151 

retains water poorly 148 

Sandy soils, how improved 175 

liable to burn out 152 

readily warmed 152 

Science, and practice 2 

definition of 1 

in common language 3 

foundation of. 22 

knowledge of 25 

Seed, composition uniform 191 

contains all elements of plant 

food 91 

formation of 191-194 

of what composed 182 

Silicic dioxide 103 

how dissolved 103 

Silicon 91 

Skim milk, analysis of 310 

value of for pigs 310 

Smoke, as a protection from frost . . 55 

Sodic chloride 106 

hydrate :......... 105 

Sodium 92 

Soil, absorption of water from air . 149 

anaJysi.s of — 157 

baking of 165 

capillary attraction 150 

chemical changes in 162 

classification of 147 

composition of 144 

condition of necessary for crop 318 
correcting defects in 173 

not to pages , 



186 



SCIENCE IN FARMING. 



Soil, exhaustion of 159 

exhaustion of under rotation .. 160 
fertility of affected by drainage 168 

of Minnesota 168 

retention of fertilizing elements 151 

retention of water by 148 

run down 161 

temperature of 152 

Soiling, how advantageous. . .* 209, *272 

Solid 17-18 

Soluble carbohydrates, use of term 227 

definition of word 67 

Solubility, difterence in 69 

Solution 66 

Starvation 220 

Straw, best in bad season 192, 231 

as a milk diet 288 

Sugar, maple how produced 189 

Sugars 122 

Superphosphates 379 

manufacture of 380 

T 

Table salt 106 

Table, air, composition of 133 

absorption of water by soils 149 

albuminoid ratio of foods 263 

albuminoids, composition of 126 

digestible constituents in foods 230 

comparative value of foods 263 

comparison animal and vegeta- 
ble substance 202 

composition of colostrum 280 

composition of farm-yard ma- 
nure 338 

composition of food 230 

composition of hay at different 

dates 232 

composition of milk 280 

composition of plants before 

and after maturity 192 

composition of solid and liquid 

excrement 349 

concentration of manures 347 

elements 83 

effects of fallow 326 

germination, temperature of. . . 184 
manure fermented In open 

barn-yard 841 

manure fermented under a shed 342 
manure left spread over a yard 343 

plants ash in one ton 180 

plants dry, water in. 179 

Numbers refer to paragraphs, 



Table, plants, fresh, water in 178 

proportion of nitrogen In In- 
crease and excrement 357 

soils, classification of 147 

soils, composition of 157 

soils, exhaustion of by wheat 159 
soils, exhaustion of under rota- 
tion 160 

soils, retention of water in 148 

soils, weight of an acre 155 

value of manures 369 

value of manurial constituents 

In food 372 

value of plant food 367 

value of rich and poor manure 347 

water in animal substance ."Oi 

Transformation of organic sub- 
stances 130 

Tricalclc phosphate ^ 110 

Tubers, storehouse of food 194 

Turnips, manure for 386 

U 

Under-feeding extravagant 270 

Urea, formed from albuminoids .207 
Urine more valuable than solid ex- 
crement 370 

rapid action as fertilizer 196 

V 

Valley of poison 136 

Volatile oils 125 

W 

Waste of fertility by drainage 156 

of the body 206 

Water 97 

amount in plants 178, 179 

capillary 97 

efiect of In food 276 

hydrostatic 97 

hygroscopic 97 

■ In air , 140 

" not absorbed by plants 141 

" prevents radiation '.. . 53 

in|animal{substances 201 

in soils requires heat to remove 50 

of combination 97 

proportion to dry food 277 

Weeds, best time to kill 195 

Weight of soils 155 

Working animal, food for 314 

Young animal, proper food for 280-284 
Young grass and clover, best for 

milk 290 

why they give good returns 243 

not to pages . 



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MIAMI VALLEY HERD OF 

POLAND CHINA SWINE 

the property of J. L. Van Doren, Glen- 
dale, Hamilton county, O. Stock for 
sale at all times. Breeders all recorded 
in Ohio P. C. Record. A correct 
pedigree furnished with all stock sold. 
All correspondents promptly answer- 
ed. Special rates by express. Ad- 
dress as above. 

Roses and Flowering- Plants. 



Sixteen forI$l— Your Selection. 



Our desci'iptive catalogue, contain- 
ing full list of NEW and desirable va- 
rieties sent FREE on application. 

Address, E. BONNER & Co., 
Xenia, Ohio. 

J. H DENHAM, 

ST. CLAIRSVILLE, Belmont Co., O., 
Breeds Registered 

POLAND CHINA SWINE 

Merino Sheep and Jersey Cattle. His- 
tory of P. C. Hog 25c. Call and see me. 
Latch string always out. 

H. S. ROSS, 

SEVILLE, MEDINA CO., OHIO, 
Breeder and shipper Improved Ches- 
ter White Swine, Pljaiiouth Rock, W. 
C. B. Polands, S. S. Polish, Pekin 
Ducks, Toulouse Geese and Bronze 
Turkeys. 

Stock for Sale at all Times: 
Eggs In Season: 

J. L. WHITON, 

NORTH AMHERST, Lorain Co., O,, 
Breeder of 

— Thoroughbred — 
SHORT-HORN CATTLE. 



JERSEY RED SWINE. 

I can now fill orders for single pigs 
or pairs or trios, not akin. Also a 
choice lot of Boars, old enough for 
service, and Sows of all ages, bred or 
not, as desired. I purchased my stock 
from Petit, of New Jersey, the cele- 
brated breeder of Jersey Reds, and it 
is all thoroughbred. Inquiries prompt- 
ly answered. SAM'L TAYLOR, 
Grove City, Franklin county, O. 

A. M. TORE, 

BUCYRUS, Crawford Co., OHIO, 
Breeder and shipper of pure 

POLAND CHINA HOGS, 

Of the most fashionable strains. All 
Breeding stock recorded in the O. P. 
C. Record. Also Plymouth Rock 
Chickens. Correspondence solicited. 



PAUL TOMLINSON, 

CEDARVILLE, Greene Co., OHIO. 
Breeder of 

SHORT-HORN CATTLE, 

Poland China Pigs, Bronze Turkeys, 
Light Brahma, Buff Cochin and Ply- 
mouth Rock Fowls. 

I). J. WHITMORE, 

CASSTOWN, MIAMI CO., OHIO, 

Makes a specialty of 
Devon Cattle, Poland 
China Hogs, Cotswold 

^ Sheep, Bronze Turkeys, 

Jjight Briihmas, Plymouth Rock and 
Houdan Chickens, White Guineas, 
Bremen and Toulouse Geese. 

" BERKSHIRES 

Boars fit for service. Sows 
bred and young stock. If 
stock is not as repre- 
sented, will pay return 
charges on it. Stock regis- 
tered. 

JOHN M. JAMISON, 

Roxabell, Ross county, Ohio. 






A. Z.&C. D.FORNEY. 

Breeders and Shippers of 
Pure 

Poland China Swine 



ii;#°Make a specialty of 
this breed. 

Reliable pedigrees fur- 
nished. 



redflffdowrta-I)vlArZfgC;D.ToRNiY?PlimfLffd, Ohipy 



PLAINFIELD, OHIO. 
Coshocton county, 



CHICAGO SCALE CO., 

U7, 149 & 151 South Jefferson street, 

MANUFACTURERS OF EVERY VARIETY OF 

U.S. Standard Scales. 



gmrihe Best Quality at the Lowest Prices 

H' 




2-Ton Wagon Scales (platform 6x12) ^40.00 

S-Ton 7x13 - ■ ■ $50.00 | 4-Ton 8x14 - - $60.00 

All other sizes in proportion. All scales perfect. 
Iron Levers, Steel Bearings, Brass Beam, Beam Box, and 
building directions with each Scale. 

^'The Little Detective," For Family or Office, $3.00. 
Family or Farm Scale 1-2 to 24 11)S., $5. 



A $23 Farmer's Forge for $IO. 

Every Farmer His Own Blacksmith- 

A Forge, Anvil and Kit of Tools, 

So any Farmer can do his own Jobbing, ONLY $20. 

Also, all sizes of Anvils, Wind Mills, Fanning Mills, Farm 
and Family Grist Mills, Hay Presses, Corn She lers Faim 
and Garden Wheelbarrows. Save Money. Get the Best. 
Send for List, 



JUST WHAT YOU WANT! 



THE RANDALL HARROW. 




The most Convenient, 
Effective, Durable and 
Reliable Harrow made. 
Economizes time,saves 
labor and money; se- 
cures the largest yield 
of crops by the rik)st 
pferfect tillage. It has 
no equal as a Pulver- 
izer, Cultivator, Sod 
Cutter, and for tilling 
all tenacious and tough 
soils. It is often a sub- 
stitute for the plow, 
cutting from six to ten 
feet in breadth. Less 
labor and increased crops are the certain results of the use of the Randall 
Harrow. Half the time saved by using it to prepare the soil for seed; and it 
adapts itself to every condition of surface and soil. Every one who has used 
it or seen it used, speaks in its praise. 

IT IS NO EXPERIMENT, BUT A PROVED SUCCESS ! 

Do Not Tramp After and Lift Your Useless Old Drag. Bide the 
Bandall, and Save Many a Weary Mile. 

From E, C. Ellis, one of the editors of the Farmers' Advance, and a prom- 
inent Granger: 

Last summer I saw an advertisement of the Randall Harrow, and liking the 
description, I opened a correspondence with the manufacturers, which re- 
sulted in my procuring one from them. After removing the fodder from my 
cornfield, I prepared the ground for wheat with the harrow alone, and I never 
had a crop put in more satisfactorily. I then got Bro. Van Doren, of Wyom- 
ing Grange— one of the best farmers— to try it, which he did successfully, and 
on returning it pronounced it the "Boss Harrow." This spring he used it again 
with the same marked success in pulverizing the soil. I also had a ten-acre 
field of clover turned under, then placed the Randall Harrow on it, and I have 
never before seen sod put in such perfect order for corn. At the last meeting 
of Wyoming Grange, Bro. G. W. Raymond, our ex-Master, stated that he had 
a clover field that he could do nothing with. He had tried all the harrows in 
the neighborhood and none could cut it. Bro. Van Doren said to him : "Get 
Bro. Ellis' 'Boss Harrow;' it will fetch it." He came, got the harrow, and I 
learn from my son that it did the work well. After so thoroughly testing it 
myself, and having two No. 1 farmers like our ex-Masters Van Doren and 
Raymond subject it to seveae tests, and getting their testimony in its favor, I 
feel justified lo raying t^at the Randall Harrow will do all that the manufac- 
turers claim, and do most cheerfully reconimend it as the best harrow I have 
ever seen. B. C. ELLIS, Glendale, Ohio. 

From M. W. Dunham, the largest breeder and importer of Norman and 
Percheron horses in the United States : 

I never bought a machine I was so well satisfied to pay for as the Randall 
Harrow. I have thoroughly tested it on nearly all kinds of ground, corn stub- 
ble, sod breaking and fall plowing. No other implement can approach it for 
completeness of work and economy of power in surface cultivation. I am 
sure you will have success, for the harrow needs only to be used to commend 
itseu as the most valuable implement in use. All purchasers will find, as I 
have, that you conferred a favor by placing the Randall Harrow within their 
reach. M. W. DUNHAM, Oak Lawn Farm, Wayne, 111. 

We would be pleased to mail descriptive circulars to any one applying. 
Agents wanted in unoccupied territory. 

J. W. STODDARD & CO., Dayton, Ohio, Manufacturers. 



THE BIG GIANT AND MOUND CITY 




OUR LATEST INVENTION. 

The most rapid Grinder ever made. We 
make the only Corn and Cob Mill with 
Cast Steel Grinders. If we fail to furnish 
proof, will give yon a mill. Ten di fie rent 
styles and sizes. The only mill that sifts 
the meal. Grinds shelled corn, makes good 



family meal and grincls all kinds of small grain. 



STAR CANE MILL 

Grinds twice as fast. Double the capacity. 

CHEAPEST MILL MADE. 

WAEEA^S'TED in every respect. We man- 
ufacture TE:N^ DIFFERENT STYLES of 
Cane Mills and a full stock of Evaporators 
and 

SUGAR MAKERS* SUPPLIES. 




STUBB'S EVAPORATOR. 




A boy 14 Years Old 
Can Operate It, 

Saves fuel and LABOR, 
makes double the quanti- 
ty, a perfect defecator, 
saves 90 per cent, of labor 
in skimming, produces a 
better quality of syrup. §^tF' This Evaporator made the 
syrup that was awarded the highest premium — viz. §75 — at the 
great St. Louis Fair in 1882. 

JlPI^Send for circulars and prices. 

J. A. FIELD & Co., St. Louis, Mo., 
1622 to 1628 N. Eighth St., and 714 to 724 Howard St. 



— SHOULl) Subscribe fok the — 

FARM AND FIRESIDE, 

The Leading Agricultural, and Home Journal 
of America. 



ONLY 50 CENTS A YEAR. 



LIBERAL PREMIUMS 

— AND — 

em- CASH COMMISSIONS 

Given Those Who Get Up Clubs. 



&f- Sample Copy and Premium List SENT FREE 



UPON APPLICATION. 

Address, 



MAST, CROWELL & KIRKPATRICK, 

Spring-fleld, Ohio, and Louisville, Ky. 



— ALSO PUBLISHERS OF — 

OUR YOUNG PEOPLE, 

A Handsomely Illustrated Paper for Young People. 



ONE DOLLAR PER YEAR. 

Address, MAST, CROWELL & KIRKPATRICK, 

Springfield, 0., and Louisville, Ky. 






LIBRARY OF CONGRESS 



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